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    <link:label id="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_43648D4FC951A19AAFA055F83CB16A2F_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_43648D4FC951A19AAFA055F83CB16A2F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Liability, Payments, Due Year Three</link:label>
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    <link:label id="lab_us-gaap_DerivativeAssets_87FB37F46D9E9F961F1174CF0F9956EF_label_en-US" xlink:label="lab_us-gaap_DerivativeAssets_87FB37F46D9E9F961F1174CF0F9956EF" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Derivative Asset</link:label>
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    <link:label id="lab_us-gaap_LongTermDebt_75B613175DDCEB48CF3B74CF0F9A3D97_label_en-US" xlink:label="lab_us-gaap_LongTermDebt_75B613175DDCEB48CF3B74CF0F9A3D97" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Long-term Debt</link:label>
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    <link:loc xlink:href="ofc-20190331.xsd#ofc_ForwardEquitySaleAgreementMember" xlink:label="loc_ofc_ForwardEquitySaleAgreementMember_0752CED31067DEE17A9C7E74A1CD592C" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_88E8512D0A323E67C4107E74A1CEB6B7" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_B66A25BE21DE1B6B76657E74A1CE9FEF" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_B66A25BE21DE1B6B76657E74A1CE9FEF" xlink:to="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_B66A25BE21DE1B6B76657E74A1CE9FEF" xlink:type="arc" />
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    <link:loc xlink:href="ofc-20190331.xsd#ofc_ComprehensiveIncomeLossNetOfTaxAfterRedeemableNoncontrollingInterestAdjustments" xlink:label="loc_ofc_ComprehensiveIncomeLossNetOfTaxAfterRedeemableNoncontrollingInterestAdjustments_BE02086008E6CA66BA8B7E74A1D0243E" xlink:type="locator" />
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    <link:label id="lab_us-gaap_Dividends_091A7EF84E2948BC328A7E74A1D055C1_negatedLabel_en-US" xlink:label="lab_us-gaap_Dividends_091A7EF84E2948BC328A7E74A1D055C1" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Dividends/Distributions</link:label>
    <link:label id="lab_us-gaap_Dividends_091A7EF84E2948BC328A7E74A1D055C1_label_en-US" xlink:label="lab_us-gaap_Dividends_091A7EF84E2948BC328A7E74A1D055C1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Dividends</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Dividends" xlink:label="loc_us-gaap_Dividends_091A7EF84E2948BC328A7E74A1D055C1" xlink:type="locator" />
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    <link:label id="lab_us-gaap_PreferredUnitsOutstanding_6BAFE34EBD430B3F75C97E74A1D15BC6_periodEndLabel_en-US" xlink:label="lab_us-gaap_PreferredUnitsOutstanding_6BAFE34EBD430B3F75C97E74A1D15BC6" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance (preferred units)</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PreferredUnitsOutstanding" xlink:label="loc_us-gaap_PreferredUnitsOutstanding_6BAFE34EBD430B3F75C97E74A1D15BC6" xlink:type="locator" />
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    <link:label id="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7588742BECFEA0457D327E74A1D2F96E_periodEndLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7588742BECFEA0457D327E74A1D2F96E" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xml:lang="en-US">Balance (COPT: 102,150,358 and 111,939,790 shares as of March 31, 2018 and 2019, respectively)</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7588742BECFEA0457D327E74A1D2F96E" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract" xlink:label="loc_us-gaap_EquityMethodInvestmentsAndJointVenturesAbstract_40FAFDE2B7D2AFED75C57E750F80A147" xlink:type="locator" />
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    <link:label id="lab_ofc_RealEstateJointVenturesTable_ED88699EC030F519D8A87E750F80F748_label_en-US" xlink:label="lab_ofc_RealEstateJointVenturesTable_ED88699EC030F519D8A87E750F80F748" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Real Estate, Joint Ventures [Table]</link:label>
    <link:label id="lab_ofc_RealEstateJointVenturesTable_ED88699EC030F519D8A87E750F80F748_documentation_en-US" xlink:label="lab_ofc_RealEstateJointVenturesTable_ED88699EC030F519D8A87E750F80F748" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Tabular disclosure of information related to unconsolidated and consolidated real estate joint ventures.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RealEstateJointVenturesTable" xlink:label="loc_ofc_RealEstateJointVenturesTable_ED88699EC030F519D8A87E750F80F748" xlink:type="locator" />
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    <link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_C821CBDEE7195C2F64427EA52AC42CD0_terseLabel_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis_C821CBDEE7195C2F64427EA52AC42CD0" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segments [Axis]</link:label>
    <link:label id="lab_us-gaap_StatementBusinessSegmentsAxis_C821CBDEE7195C2F64427EA52AC42CD0_label_en-US" xlink:label="lab_us-gaap_StatementBusinessSegmentsAxis_C821CBDEE7195C2F64427EA52AC42CD0" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_C821CBDEE7195C2F64427EA52AC42CD0" xlink:type="locator" />
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    <link:label id="lab_us-gaap_SegmentDomain_072F24D390841687B63B7EA52AC55A5A_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentDomain_072F24D390841687B63B7EA52AC55A5A" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Segments [Domain]</link:label>
    <link:label id="lab_us-gaap_SegmentDomain_072F24D390841687B63B7EA52AC55A5A_label_en-US" xlink:label="lab_us-gaap_SegmentDomain_072F24D390841687B63B7EA52AC55A5A" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segments [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_072F24D390841687B63B7EA52AC55A5A" xlink:type="locator" />
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    <link:label id="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C_terseLabel_en-US" xlink:label="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Data Center Shells</link:label>
    <link:label id="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C_label_en-US" xlink:label="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Data Center Shells [Member]</link:label>
    <link:label id="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C_documentation_en-US" xlink:label="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Data Center Shells [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_DataCenterShellsMember" xlink:label="loc_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C" xlink:to="lab_ofc_DataCenterShellsMember_5F28F92005935C289EF77EA52B02AF3C" xlink:type="arc" />
    <link:label id="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107_terseLabel_en-US" xlink:label="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Real Estate Property Classification [Axis]</link:label>
    <link:label id="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107_label_en-US" xlink:label="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Real Estate Property Classification [Axis]</link:label>
    <link:label id="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107_documentation_en-US" xlink:label="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information regarding classification of real estate properties.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RealEstatePropertyClassificationAxis" xlink:label="loc_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107" xlink:to="lab_ofc_RealEstatePropertyClassificationAxis_96DEC93848277E87B5037EA52A7AE107" xlink:type="arc" />
    <link:label id="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378_terseLabel_en-US" xlink:label="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Real Estate Property Classification [Domain]</link:label>
    <link:label id="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378_label_en-US" xlink:label="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Real Estate Property Classification [Domain]</link:label>
    <link:label id="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378_documentation_en-US" xlink:label="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents classification of real estate properties.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RealEstatePropertyClassificationDomain" xlink:label="loc_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378" xlink:to="lab_ofc_RealEstatePropertyClassificationDomain_6584573941F2080668287EA52A871378" xlink:type="arc" />
    <link:label id="lab_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402_terseLabel_en-US" xlink:label="lab_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating Properties</link:label>
    <link:label id="lab_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402_label_en-US" xlink:label="lab_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Properties [Member]</link:label>
    <link:label id="lab_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402_documentation_en-US" xlink:label="lab_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents information pertaining to operating properties of the entity.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_OperatingPropertiesMember" xlink:label="loc_ofc_OperatingPropertiesMember_F3E19E7746BE7795C8777EA52BAE7402" xlink:type="locator" />
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    <link:label id="lab_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Real Estate Properties [Axis]</link:label>
    <link:label id="lab_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B_label_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Real Estate Property Ownership [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RealEstatePropertiesAxis" xlink:label="loc_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B" xlink:to="lab_us-gaap_RealEstatePropertiesAxis_FB078541D3B93374ED5A7E750F80481B" xlink:type="arc" />
    <link:label id="lab_us-gaap_RealEstatePropertiesDomain_C99EEC161766530C047C7E750F80F7C5_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesDomain_C99EEC161766530C047C7E750F80F7C5" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Real Estate Properties [Domain]</link:label>
    <link:label id="lab_us-gaap_RealEstatePropertiesDomain_C99EEC161766530C047C7E750F80F7C5_label_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesDomain_C99EEC161766530C047C7E750F80F7C5" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Real Estate Properties [Domain]</link:label>
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    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RealEstatePropertiesDomain_C99EEC161766530C047C7E750F80F7C5" xlink:to="lab_us-gaap_RealEstatePropertiesDomain_C99EEC161766530C047C7E750F80F7C5" xlink:type="arc" />
    <link:label id="lab_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8_terseLabel_en-US" xlink:label="lab_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Single-tenant data centers</link:label>
    <link:label id="lab_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8_label_en-US" xlink:label="lab_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Single-tenant Data Centers [Member]</link:label>
    <link:label id="lab_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8_documentation_en-US" xlink:label="lab_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents single-tenant data centers owned by the entity.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_SingletenantDataCentersMember" xlink:label="loc_ofc_SingletenantDataCentersMember_922F0FF358194E1E19E37E750F81BFA8" xlink:type="locator" />
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    <link:label id="lab_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_1D9EDA2B237A129E173C7E750F829FC0_terseLabel_en-US" xlink:label="lab_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_1D9EDA2B237A129E173C7E750F829FC0" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable Interest Entities [Axis]</link:label>
    <link:label id="lab_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_1D9EDA2B237A129E173C7E750F829FC0_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_1D9EDA2B237A129E173C7E750F829FC0" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entities [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis" xlink:label="loc_us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis_1D9EDA2B237A129E173C7E750F829FC0" xlink:type="locator" />
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    <link:label id="lab_us-gaap_ClassificationOfVariableInterestEntityDomain_5B64C78198C8EC200E0F7E750F82A0D8_label_en-US" xlink:label="lab_us-gaap_ClassificationOfVariableInterestEntityDomain_5B64C78198C8EC200E0F7E750F82A0D8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Classification [Domain]</link:label>
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    <link:label id="lab_ofc_MSquareAssociatesLlcMember_CE0CEF8CD42587E649727E750F83C256_terseLabel_en-US" xlink:label="lab_ofc_MSquareAssociatesLlcMember_CE0CEF8CD42587E649727E750F83C256" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">M Square Associates, LLC</link:label>
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    <link:label id="lab_ofc_GICOPTDCPartnershipLLCMember_39ABCF99C0B9084312D17E750F84C7FE_terseLabel_en-US" xlink:label="lab_ofc_GICOPTDCPartnershipLLCMember_39ABCF99C0B9084312D17E750F84C7FE" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">GI-COPT</link:label>
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    <link:label id="lab_ofc_GICOPTDCPartnershipLLCMember_39ABCF99C0B9084312D17E750F84C7FE_documentation_en-US" xlink:label="lab_ofc_GICOPTDCPartnershipLLCMember_39ABCF99C0B9084312D17E750F84C7FE" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">GI-COPT DC Partnership LLC [Member]</link:label>
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    <link:label id="lab_ofc_RealEstateJointVentureLineItems_CE756BB3C23DD8C619BD7E750F8428F6_terseLabel_en-US" xlink:label="lab_ofc_RealEstateJointVentureLineItems_CE756BB3C23DD8C619BD7E750F8428F6" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments in real estate joint ventures</link:label>
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    <link:label id="lab_us-gaap_VariableInterestEntityOwnershipPercentage_44921A8DE6924B40098E7E750F85B039_label_en-US" xlink:label="lab_us-gaap_VariableInterestEntityOwnershipPercentage_44921A8DE6924B40098E7E750F85B039" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableInterestEntityOwnershipPercentage" xlink:label="loc_us-gaap_VariableInterestEntityOwnershipPercentage_44921A8DE6924B40098E7E750F85B039" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets" xlink:label="loc_us-gaap_VariableInterestEntityConsolidatedCarryingAmountAssets_580356319999FE393A617E750F85AC2C" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PledgedAssetsNotSeparatelyReportedRealEstate" xlink:label="loc_us-gaap_PledgedAssetsNotSeparatelyReportedRealEstate_3DF938319E286F737D877E750F850952" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_F4DC1D0B07E6E1697C897E750F859AE0" xlink:type="locator" />
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    <link:label id="lab_us-gaap_DebtInstrumentAxis_732252DDED95420984868F6F61E1C696_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentAxis_732252DDED95420984868F6F61E1C696" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument [Axis]</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentNameDomain_723C29B47D8785F405AB8F6F61E217E8_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain_723C29B47D8785F405AB8F6F61E217E8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Debt Instrument, Name [Domain]</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentNameDomain_723C29B47D8785F405AB8F6F61E217E8_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain_723C29B47D8785F405AB8F6F61E217E8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Name [Domain]</link:label>
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    <link:label id="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034_terseLabel_en-US" xlink:label="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fixed rate mortgage debt</link:label>
    <link:label id="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034_label_en-US" xlink:label="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fixed Rate Secured Debt [Member]</link:label>
    <link:label id="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034_documentation_en-US" xlink:label="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">A collateralized debt obligation (backed by pledge, mortgage or other lien on the entity's assets) bearing fixed interest rates.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_FixedRateSecuredDebtMember" xlink:label="loc_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034" xlink:to="lab_ofc_FixedRateSecuredDebtMember_B04434A9E5AB733CAC828F6F61E22034" xlink:type="arc" />
    <link:label id="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0_verboseLabel_en-US" xlink:label="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Variable-rate debt</link:label>
    <link:label id="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0_label_en-US" xlink:label="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Variable Rate Debt [Member]</link:label>
    <link:label id="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0_documentation_en-US" xlink:label="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Variable Rate Debt</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_VariableRateDebtMember" xlink:label="loc_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0" xlink:to="lab_ofc_VariableRateDebtMember_9772ADBC6F8AA229B6718F6F61E249F0" xlink:type="arc" />
    <link:label id="lab_us-gaap_ConstructionLoanPayableMember_56819AB65FBACE9D509C8F6F61E27BD7_terseLabel_en-US" xlink:label="lab_us-gaap_ConstructionLoanPayableMember_56819AB65FBACE9D509C8F6F61E27BD7" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction Loan</link:label>
    <link:label id="lab_us-gaap_ConstructionLoanPayableMember_56819AB65FBACE9D509C8F6F61E27BD7_label_en-US" xlink:label="lab_us-gaap_ConstructionLoanPayableMember_56819AB65FBACE9D509C8F6F61E27BD7" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction Loan Payable [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ConstructionLoanPayableMember" xlink:label="loc_us-gaap_ConstructionLoanPayableMember_56819AB65FBACE9D509C8F6F61E27BD7" xlink:type="locator" />
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    <link:label id="lab_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9_terseLabel_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Revolving Credit Facility</link:label>
    <link:label id="lab_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9_label_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revolving Credit Facility [Member]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9" xlink:to="lab_us-gaap_RevolvingCreditFacilityMember_726C4A64939DFEBEDFFF8F6F61E36DD9" xlink:type="arc" />
    <link:label id="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E_terseLabel_en-US" xlink:label="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Term Loan Facility</link:label>
    <link:label id="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E_label_en-US" xlink:label="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Term Loan Facility [Member]</link:label>
    <link:label id="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E_documentation_en-US" xlink:label="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents unsecured term loan agreements entered into by entity.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_TermLoanFacilityMember" xlink:label="loc_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E" xlink:to="lab_ofc_TermLoanFacilityMember_E99128CC181D4B47A57A8F6F61E34E5E" xlink:type="arc" />
    <link:label id="lab_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471_terseLabel_en-US" xlink:label="lab_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">3.600% Senior Notes</link:label>
    <link:label id="lab_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471_label_en-US" xlink:label="lab_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">3.60% Senior Notes [Member]</link:label>
    <link:label id="lab_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471_documentation_en-US" xlink:label="lab_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">3.60% Senior Notes [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_A3.60SeniorNotesMember" xlink:label="loc_ofc_A3.60SeniorNotesMember_9C5E8395C788E346B5A78F6F61E3F471" xlink:type="locator" />
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    <link:label id="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5_terseLabel_en-US" xlink:label="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">5.250% Senior Notes</link:label>
    <link:label id="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5_label_en-US" xlink:label="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">5.250% Senior Notes [Member]</link:label>
    <link:label id="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5_documentation_en-US" xlink:label="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">5.250% Senior Notes [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_A5.250SeniorNotesMember" xlink:label="loc_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5" xlink:to="lab_ofc_A5.250SeniorNotesMember_770CCC7EA051F41AF1ED8F6F61E310B5" xlink:type="arc" />
    <link:label id="lab_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2_terseLabel_en-US" xlink:label="lab_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">3.700% Senior Notes</link:label>
    <link:label id="lab_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2_label_en-US" xlink:label="lab_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">3.70% Senior Notes [Member]</link:label>
    <link:label id="lab_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2_documentation_en-US" xlink:label="lab_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">3.70SeniorNotes [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_A3.70SeniorNotesMember" xlink:label="loc_ofc_A3.70SeniorNotesMember_0FCC3A506DD62D85B7968F6F61E308B2" xlink:type="locator" />
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    <link:label id="lab_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2_terseLabel_en-US" xlink:label="lab_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">5.000% Senior Notes</link:label>
    <link:label id="lab_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2_label_en-US" xlink:label="lab_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Five Percent Senior Notes [Member]</link:label>
    <link:label id="lab_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2_documentation_en-US" xlink:label="lab_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Five Percent Senior Notes [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_FivePercentSeniorNotesMember" xlink:label="loc_ofc_FivePercentSeniorNotesMember_D084F6C601FC2364A9BC8F6F61E4C3E2" xlink:type="locator" />
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    <link:label id="lab_us-gaap_NotesPayableOtherPayablesMember_91F6DBF9B8E33EE820AC8F6F61E41C05_terseLabel_en-US" xlink:label="lab_us-gaap_NotesPayableOtherPayablesMember_91F6DBF9B8E33EE820AC8F6F61E41C05" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unsecured notes payable</link:label>
    <link:label id="lab_us-gaap_NotesPayableOtherPayablesMember_91F6DBF9B8E33EE820AC8F6F61E41C05_label_en-US" xlink:label="lab_us-gaap_NotesPayableOtherPayablesMember_91F6DBF9B8E33EE820AC8F6F61E41C05" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Notes Payable, Other Payables [Member]</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_232BFEACBAFCE3C6662A8F6F61EE379E_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_232BFEACBAFCE3C6662A8F6F61EE379E" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest rate (as a percent)</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_232BFEACBAFCE3C6662A8F6F61EE379E_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_232BFEACBAFCE3C6662A8F6F61EE379E" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate, Stated Percentage</link:label>
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    <link:label id="lab_us-gaap_DeferredFinanceCostsNet_D591919FB9BF70CDD5E68F6F61EE7C44_label_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsNet_D591919FB9BF70CDD5E68F6F61EE7C44" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Issuance Costs, Net</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentUnamortizedPremium_E3913C96FF3E20694C908F6F61EEF4B5_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedPremium_E3913C96FF3E20694C908F6F61EEF4B5" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unamortized premium included in carrying value</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_637CD91597EB3BF414688F6F61EFAE7D_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_637CD91597EB3BF414688F6F61EFAE7D" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Remaining borrowing capacity</link:label>
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    <link:label id="lab_ofc_LineofCreditFacilityMaturityDateExtensionNumberofExtensions_CDD8442D420681B45E4F8F6F61EFFE27_terseLabel_en-US" xlink:label="lab_ofc_LineofCreditFacilityMaturityDateExtensionNumberofExtensions_CDD8442D420681B45E4F8F6F61EFFE27" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of extensions</link:label>
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    <link:loc xlink:href="ofc-20190331.xsd#ofc_LineofCreditFacilityMaturityDateExtensionNumberofExtensions" xlink:label="loc_ofc_LineofCreditFacilityMaturityDateExtensionNumberofExtensions_CDD8442D420681B45E4F8F6F61EFFE27" xlink:type="locator" />
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    <link:label id="lab_ofc_DebtInstrumentExtensionOptionTerm_A3E9245193EB9012785A8F6F61EF5078_terseLabel_en-US" xlink:label="lab_ofc_DebtInstrumentExtensionOptionTerm_A3E9245193EB9012785A8F6F61EF5078" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Extension option period (in years)</link:label>
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    <link:label id="lab_ofc_DebtInstrumentExtensionOptionTerm_A3E9245193EB9012785A8F6F61EF5078_documentation_en-US" xlink:label="lab_ofc_DebtInstrumentExtensionOptionTerm_A3E9245193EB9012785A8F6F61EF5078" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the period over which the debt may be extended at the option of the entity, subject to certain conditions.</link:label>
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    <link:label id="lab_ofc_LineofCreditFacilityExtensionFeePercentage_58C00F9409E6BE95A0DB8F6F61EF117C_terseLabel_en-US" xlink:label="lab_ofc_LineofCreditFacilityExtensionFeePercentage_58C00F9409E6BE95A0DB8F6F61EF117C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Line of credit facility, extension fee percentage</link:label>
    <link:label id="lab_ofc_LineofCreditFacilityExtensionFeePercentage_58C00F9409E6BE95A0DB8F6F61EF117C_label_en-US" xlink:label="lab_ofc_LineofCreditFacilityExtensionFeePercentage_58C00F9409E6BE95A0DB8F6F61EF117C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Extension Fee Percentage</link:label>
    <link:label id="lab_ofc_LineofCreditFacilityExtensionFeePercentage_58C00F9409E6BE95A0DB8F6F61EF117C_documentation_en-US" xlink:label="lab_ofc_LineofCreditFacilityExtensionFeePercentage_58C00F9409E6BE95A0DB8F6F61EF117C" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Line of Credit Facility, Extension Fee Percentage</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscount_B79689F49AC16D0873E68F6F61F04E93_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscount_B79689F49AC16D0873E68F6F61F04E93" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Unamortized discount included in carrying value</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentInterestRateEffectivePercentage_9782A7EDD60C2BADECDA8F6F61F0B66C_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateEffectivePercentage_9782A7EDD60C2BADECDA8F6F61F0B66C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Effective interest rate on debt (as a percent)</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentInterestRateEffectivePercentage_9782A7EDD60C2BADECDA8F6F61F0B66C_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateEffectivePercentage_9782A7EDD60C2BADECDA8F6F61F0B66C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Debt Instrument, Interest Rate, Effective Percentage</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_9782A7EDD60C2BADECDA8F6F61F0B66C" xlink:type="locator" />
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    <link:label id="lab_us-gaap_InterestCostsCapitalized_01018885A215A38EAFB98F6F61F0DAB4_terseLabel_en-US" xlink:label="lab_us-gaap_InterestCostsCapitalized_01018885A215A38EAFB98F6F61F0DAB4" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest costs capitalized</link:label>
    <link:label id="lab_us-gaap_InterestCostsCapitalized_01018885A215A38EAFB98F6F61F0DAB4_label_en-US" xlink:label="lab_us-gaap_InterestCostsCapitalized_01018885A215A38EAFB98F6F61F0DAB4" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Costs Capitalized</link:label>
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    <link:label id="lab_us-gaap_SegmentReportingAbstract_1DF399BC019D6139A935560E1567C4CD_label_en-US" xlink:label="lab_us-gaap_SegmentReportingAbstract_1DF399BC019D6139A935560E1567C4CD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_1DF399BC019D6139A935560E1567C4CD" xlink:type="locator" />
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    <link:label id="lab_us-gaap_SegmentReportingDisclosureTextBlock_28E089D5A0626E91994D560E15672874_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingDisclosureTextBlock_28E089D5A0626E91994D560E15672874" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Information by Business Segment</link:label>
    <link:label id="lab_us-gaap_SegmentReportingDisclosureTextBlock_28E089D5A0626E91994D560E15672874_label_en-US" xlink:label="lab_us-gaap_SegmentReportingDisclosureTextBlock_28E089D5A0626E91994D560E15672874" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Segment Reporting Disclosure [Text Block]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="loc_us-gaap_SegmentReportingDisclosureTextBlock_28E089D5A0626E91994D560E15672874" xlink:type="locator" />
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    <link:label id="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_CD0F262F1BDB634F20567AF7532EDDBB_label_en-US" xlink:label="lab_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_CD0F262F1BDB634F20567AF7532EDDBB" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_CD0F262F1BDB634F20567AF7532EDDBB" xlink:type="locator" />
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    <link:label id="lab_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413_terseLabel_en-US" xlink:label="lab_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Real Estate [Table]</link:label>
    <link:label id="lab_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413_label_en-US" xlink:label="lab_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Real Estate [Table]</link:label>
    <link:label id="lab_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413_documentation_en-US" xlink:label="lab_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule that includes carrying amount of properties, accumulated depreciation and other information for real estate properties, by status.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ScheduleOfRealEstateTable" xlink:label="loc_ofc_ScheduleOfRealEstateTable_0865DE768D692E0620447AF7532EA413" xlink:type="locator" />
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    <link:label id="lab_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD_terseLabel_en-US" xlink:label="lab_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Real Estate Properties Status [Axis]</link:label>
    <link:label id="lab_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD_label_en-US" xlink:label="lab_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Real Estate Properties Status [Axis]</link:label>
    <link:label id="lab_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD_documentation_en-US" xlink:label="lab_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Information by status of the property.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RealEstatePropertiesStatusAxis" xlink:label="loc_ofc_RealEstatePropertiesStatusAxis_5735322D920FC0F000AB7AF7532F4CFD" xlink:type="locator" />
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    <link:label id="lab_ofc_RealEstatePropertiesStatusDomain_4AF2A82387BF17E6419F7AF7532FBA58_terseLabel_en-US" xlink:label="lab_ofc_RealEstatePropertiesStatusDomain_4AF2A82387BF17E6419F7AF7532FBA58" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Real Estate Properties Status [Domain]</link:label>
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    <link:label id="lab_ofc_RealEstatePropertiesStatusDomain_4AF2A82387BF17E6419F7AF7532FBA58_documentation_en-US" xlink:label="lab_ofc_RealEstatePropertiesStatusDomain_4AF2A82387BF17E6419F7AF7532FBA58" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the status of the property.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RealEstatePropertiesStatusDomain" xlink:label="loc_ofc_RealEstatePropertiesStatusDomain_4AF2A82387BF17E6419F7AF7532FBA58" xlink:type="locator" />
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    <link:label id="lab_ofc_PropertiesUnderConstructionRedevelopmentorContractuallyCommittedforConstructionMember_F135433A1D2963DBEE107AF75330C5A8_terseLabel_en-US" xlink:label="lab_ofc_PropertiesUnderConstructionRedevelopmentorContractuallyCommittedforConstructionMember_F135433A1D2963DBEE107AF75330C5A8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Properties under, or contractually committed for, construction or approved for redevelopment</link:label>
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    <link:label id="lab_ofc_PropertiesUnderConstructionRedevelopmentorContractuallyCommittedforConstructionMember_F135433A1D2963DBEE107AF75330C5A8_documentation_en-US" xlink:label="lab_ofc_PropertiesUnderConstructionRedevelopmentorContractuallyCommittedforConstructionMember_F135433A1D2963DBEE107AF75330C5A8" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents properties under, or contractually committed for, construction or approved for redevelopment.</link:label>
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    <link:label id="lab_ofc_LandControlledforFutureDevelopmentMember_5596627AA2BEA10D20657AF75330C4ED_terseLabel_en-US" xlink:label="lab_ofc_LandControlledforFutureDevelopmentMember_5596627AA2BEA10D20657AF75330C4ED" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Land controlled for future development</link:label>
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    <link:label id="lab_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC_terseLabel_en-US" xlink:label="lab_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other Land</link:label>
    <link:label id="lab_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC_label_en-US" xlink:label="lab_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Land [Member]</link:label>
    <link:label id="lab_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC_documentation_en-US" xlink:label="lab_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Other Land [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_OtherLandMember" xlink:label="loc_ofc_OtherLandMember_335CF4E82A8B79A7C3EC7AF75330A8DC" xlink:type="locator" />
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    <link:label id="lab_ofc_WholesaleDataCenterMember_FB7F08F91113A601AF6D7AF753308C87_terseLabel_en-US" xlink:label="lab_ofc_WholesaleDataCenterMember_FB7F08F91113A601AF6D7AF753308C87" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Operating wholesale data center</link:label>
    <link:label id="lab_ofc_WholesaleDataCenterMember_FB7F08F91113A601AF6D7AF753308C87_label_en-US" xlink:label="lab_ofc_WholesaleDataCenterMember_FB7F08F91113A601AF6D7AF753308C87" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Wholesale Data Center [Member]</link:label>
    <link:label id="lab_ofc_WholesaleDataCenterMember_FB7F08F91113A601AF6D7AF753308C87_documentation_en-US" xlink:label="lab_ofc_WholesaleDataCenterMember_FB7F08F91113A601AF6D7AF753308C87" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the wholesale data center segment of the entity.</link:label>
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    <link:label id="lab_ofc_OfficePropertiesMember_E85BE4F77E682E2CF3407AF7533184F4_documentation_en-US" xlink:label="lab_ofc_OfficePropertiesMember_E85BE4F77E682E2CF3407AF7533184F4" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Office Properties [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_OfficePropertiesMember" xlink:label="loc_ofc_OfficePropertiesMember_E85BE4F77E682E2CF3407AF7533184F4" xlink:type="locator" />
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    <link:label id="lab_ofc_PartiallyOperationalPropertiesMember_9D2927B9313E7F7E11577AF753319028_terseLabel_en-US" xlink:label="lab_ofc_PartiallyOperationalPropertiesMember_9D2927B9313E7F7E11577AF753319028" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Partially operational properties</link:label>
    <link:label id="lab_ofc_PartiallyOperationalPropertiesMember_9D2927B9313E7F7E11577AF753319028_label_en-US" xlink:label="lab_ofc_PartiallyOperationalPropertiesMember_9D2927B9313E7F7E11577AF753319028" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Partially Operational Properties [Member]</link:label>
    <link:label id="lab_ofc_PartiallyOperationalPropertiesMember_9D2927B9313E7F7E11577AF753319028_documentation_en-US" xlink:label="lab_ofc_PartiallyOperationalPropertiesMember_9D2927B9313E7F7E11577AF753319028" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents office properties under construction or redevelopment which are owned by the entity and which are partially operational.</link:label>
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    <link:label id="lab_us-gaap_RealEstatePropertiesLineItems_278137420DE6DF990E7F7AF75331D2BC_terseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesLineItems_278137420DE6DF990E7F7AF75331D2BC" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments in real estate</link:label>
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    <link:label id="lab_us-gaap_EquityAbstract_CC208A06EA00C274703D8ED1DB5EF4BB_label_en-US" xlink:label="lab_us-gaap_EquityAbstract_CC208A06EA00C274703D8ED1DB5EF4BB" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Equity [Abstract]</link:label>
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    <link:label id="lab_ofc_TwoThousandEighteenCommonStockAttheMarketProgramMember_1DF033445D4125FF15148ED1DB601198_terseLabel_en-US" xlink:label="lab_ofc_TwoThousandEighteenCommonStockAttheMarketProgramMember_1DF033445D4125FF15148ED1DB601198" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2018 Common Stock Issued to Public Under At-the-Market Program</link:label>
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    <link:label id="lab_us-gaap_ClassOfStockLineItems_6B42CC155329CE8CA7DC8ED1DB617FB8_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems_6B42CC155329CE8CA7DC8ED1DB617FB8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Class of Stock [Line Items]</link:label>
    <link:label id="lab_us-gaap_ClassOfStockLineItems_6B42CC155329CE8CA7DC8ED1DB617FB8_label_en-US" xlink:label="lab_us-gaap_ClassOfStockLineItems_6B42CC155329CE8CA7DC8ED1DB617FB8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Class of Stock [Line Items]</link:label>
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    <link:label id="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_E1946B2971E0037350BF8ED1DB6138F8_terseLabel_en-US" xlink:label="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_E1946B2971E0037350BF8ED1DB6138F8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of shares issued</link:label>
    <link:label id="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_E1946B2971E0037350BF8ED1DB6138F8_label_en-US" xlink:label="lab_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_E1946B2971E0037350BF8ED1DB6138F8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Sale of Stock, Number of Shares Issued in Transaction</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_E1946B2971E0037350BF8ED1DB6138F8" xlink:type="locator" />
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    <link:label id="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_C887A80322D718E8FDF18ED1DB61705E_verboseLabel_en-US" xlink:label="lab_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_C887A80322D718E8FDF18ED1DB61705E" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Proceeds from common shares issued under forward equity sale agreements</link:label>
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    <link:label id="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_7251BDB0327F964761C18ED1DB61A2CC_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_7251BDB0327F964761C18ED1DB61A2CC" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Remaining capacity under program</link:label>
    <link:label id="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_7251BDB0327F964761C18ED1DB61A2CC_label_en-US" xlink:label="lab_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_7251BDB0327F964761C18ED1DB61A2CC" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Stock, Capital Shares Reserved for Future Issuance</link:label>
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    <link:label id="lab_ofc_AtMarketStockOfferingProgramEstablishedRemainingCapacity_2BD84D34F54BDA23ECFD8EDFE6D5371C_terseLabel_en-US" xlink:label="lab_ofc_AtMarketStockOfferingProgramEstablishedRemainingCapacity_2BD84D34F54BDA23ECFD8EDFE6D5371C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Aggregate gross sales price</link:label>
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    <link:label id="lab_ofc_InterestRateSwapEffectiveJune302020ThreeMember_1BFD9E7818D54E9255387BE1DB661DAD_label_en-US" xlink:label="lab_ofc_InterestRateSwapEffectiveJune302020ThreeMember_1BFD9E7818D54E9255387BE1DB661DAD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Effective June 30, 2020, Three [Member]</link:label>
    <link:label id="lab_ofc_InterestRateSwapEffectiveJune302020ThreeMember_1BFD9E7818D54E9255387BE1DB661DAD_documentation_en-US" xlink:label="lab_ofc_InterestRateSwapEffectiveJune302020ThreeMember_1BFD9E7818D54E9255387BE1DB661DAD" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Interest Rate Swap, Effective June 30, 2020, Three [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_InterestRateSwapEffectiveJune302020ThreeMember" xlink:label="loc_ofc_InterestRateSwapEffectiveJune302020ThreeMember_1BFD9E7818D54E9255387BE1DB661DAD" xlink:type="locator" />
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    <link:label id="lab_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C_terseLabel_en-US" xlink:label="lab_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest rate derivatives (assets)</link:label>
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    <link:label id="lab_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C_documentation_en-US" xlink:label="lab_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Interest Rate Derivative Assets [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_InterestRateDerivativeAssetsMember" xlink:label="loc_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C" xlink:to="lab_ofc_InterestRateDerivativeAssetsMember_45C0261A8F9020E503487BE1DB67203C" xlink:type="arc" />
    <link:label id="lab_ofc_InterestRateDerivativeLiabilitiesMember_EC43B29248972D9AD7B27BFE24ADDC3B_terseLabel_en-US" xlink:label="lab_ofc_InterestRateDerivativeLiabilitiesMember_EC43B29248972D9AD7B27BFE24ADDC3B" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Interest rate derivative (liabilities)</link:label>
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    <link:loc xlink:href="ofc-20190331.xsd#ofc_FinanceRightofUseAssetsMember" xlink:label="loc_ofc_FinanceRightofUseAssetsMember_5D711FCFD6086FBFE4D68ED1DC9475BB" xlink:type="locator" />
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    <link:label id="lab_ofc_VehiclesandOfficeEquipmentMember_2765BDAE0BA9A52D06C28ED1DC95340B_terseLabel_en-US" xlink:label="lab_ofc_VehiclesandOfficeEquipmentMember_2765BDAE0BA9A52D06C28ED1DC95340B" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Vehicles and Office Equipment</link:label>
    <link:label id="lab_ofc_VehiclesandOfficeEquipmentMember_2765BDAE0BA9A52D06C28ED1DC95340B_label_en-US" xlink:label="lab_ofc_VehiclesandOfficeEquipmentMember_2765BDAE0BA9A52D06C28ED1DC95340B" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Vehicles and Office Equipment [Member]</link:label>
    <link:label id="lab_ofc_VehiclesandOfficeEquipmentMember_2765BDAE0BA9A52D06C28ED1DC95340B_documentation_en-US" xlink:label="lab_ofc_VehiclesandOfficeEquipmentMember_2765BDAE0BA9A52D06C28ED1DC95340B" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Vehicles and Office Equipment [Member]</link:label>
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    <link:label id="lab_ofc_LeaseRightofUseAssets_E65CAC5F0F1A70BC5BB68ED1DC96BC6D_totalLabel_en-US" xlink:label="lab_ofc_LeaseRightofUseAssets_E65CAC5F0F1A70BC5BB68ED1DC96BC6D" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total right-of-use assets</link:label>
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    <link:label id="lab_ofc_LeaseRightofUseAssets_E65CAC5F0F1A70BC5BB68ED1DC96BC6D_documentation_en-US" xlink:label="lab_ofc_LeaseRightofUseAssets_E65CAC5F0F1A70BC5BB68ED1DC96BC6D" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lease, Right-of-Use Assets</link:label>
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    <link:label id="lab_ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember_04F187548958EC42C4147E751004770C_terseLabel_en-US" xlink:label="lab_ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember_04F187548958EC42C4147E751004770C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Properties under construction or contractually committed for construction</link:label>
    <link:label id="lab_ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember_04F187548958EC42C4147E751004770C_label_en-US" xlink:label="lab_ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember_04F187548958EC42C4147E751004770C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Properties under Construction or Contractually Commited for Construction [Member]</link:label>
    <link:label id="lab_ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember_04F187548958EC42C4147E751004770C_documentation_en-US" xlink:label="lab_ofc_PropertiesUnderConstructionOrContractuallyCommitedForConstructionMember_04F187548958EC42C4147E751004770C" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents real estate office properties under construction or contractually committed for construction.</link:label>
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    <link:label id="lab_ofc_PropertiesUnderConstructionorContractuallyCommittedPartiallyOperationalMember_0FA06A0FD41E76B528867E751004FD08_documentation_en-US" xlink:label="lab_ofc_PropertiesUnderConstructionorContractuallyCommittedPartiallyOperationalMember_0FA06A0FD41E76B528867E751004FD08" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Properties Under Construction or Contractually Committed, Partially Operational [Member]</link:label>
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    <link:label id="lab_ofc_PropertiesUnderorApprovedforRedevelopmentMember_908FE7B54EDDFDF19CCE7E751005B1C2_terseLabel_en-US" xlink:label="lab_ofc_PropertiesUnderorApprovedforRedevelopmentMember_908FE7B54EDDFDF19CCE7E751005B1C2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Properties under or approved for redevelopment</link:label>
    <link:label id="lab_ofc_PropertiesUnderorApprovedforRedevelopmentMember_908FE7B54EDDFDF19CCE7E751005B1C2_label_en-US" xlink:label="lab_ofc_PropertiesUnderorApprovedforRedevelopmentMember_908FE7B54EDDFDF19CCE7E751005B1C2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Properties Under or Approved for Redevelopment [Member]</link:label>
    <link:label id="lab_ofc_PropertiesUnderorApprovedforRedevelopmentMember_908FE7B54EDDFDF19CCE7E751005B1C2_documentation_en-US" xlink:label="lab_ofc_PropertiesUnderorApprovedforRedevelopmentMember_908FE7B54EDDFDF19CCE7E751005B1C2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents real estate office properties under, or approved for, redevelopment.</link:label>
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    <link:label id="lab_us-gaap_RealEstatePropertiesLineItems_4F0EA61B5EADF4263F647E751005F5D6_verboseLabel_en-US" xlink:label="lab_us-gaap_RealEstatePropertiesLineItems_4F0EA61B5EADF4263F647E751005F5D6" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Construction Activities</link:label>
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    <link:label id="lab_us-gaap_AreaOfRealEstateProperty_085FD5E129E4598C884B7E75100519A3_terseLabel_en-US" xlink:label="lab_us-gaap_AreaOfRealEstateProperty_085FD5E129E4598C884B7E75100519A3" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Square footage of real estate properties (in square feet)</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AreaOfRealEstateProperty" xlink:label="loc_us-gaap_AreaOfRealEstateProperty_085FD5E129E4598C884B7E75100519A3" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AreaOfRealEstateProperty_085FD5E129E4598C884B7E75100519A3" xlink:to="lab_us-gaap_AreaOfRealEstateProperty_085FD5E129E4598C884B7E75100519A3" xlink:type="arc" />
    <link:label id="lab_ofc_ConsolidatedRealEstateJointVenturesTableTextBlock_065165980F247439BCA9560E15DDD7CE_terseLabel_en-US" xlink:label="lab_ofc_ConsolidatedRealEstateJointVenturesTableTextBlock_065165980F247439BCA9560E15DDD7CE" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of information related to investments in consolidated real estate joint ventures</link:label>
    <link:label id="lab_ofc_ConsolidatedRealEstateJointVenturesTableTextBlock_065165980F247439BCA9560E15DDD7CE_label_en-US" xlink:label="lab_ofc_ConsolidatedRealEstateJointVenturesTableTextBlock_065165980F247439BCA9560E15DDD7CE" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Consolidated Real Estate, Joint Ventures [Table Text Block]</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DED5461B441FA633C0548ED1DA97E337_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_DED5461B441FA633C0548ED1DA97E337" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]</link:label>
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    <link:label id="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_14ABADE2F3DAF007D34C8ED1DA9869FA_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_14ABADE2F3DAF007D34C8ED1DA9869FA" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Antidilutive Securities [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_14ABADE2F3DAF007D34C8ED1DA9869FA" xlink:type="locator" />
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    <link:label id="lab_us-gaap_AntidilutiveSecuritiesNameDomain_29A053A324AE88F097A48ED1DA9995FE_label_en-US" xlink:label="lab_us-gaap_AntidilutiveSecuritiesNameDomain_29A053A324AE88F097A48ED1DA9995FE" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Antidilutive Securities, Name [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_29A053A324AE88F097A48ED1DA9995FE" xlink:type="locator" />
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    <link:label id="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E_terseLabel_en-US" xlink:label="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conversion of common units</link:label>
    <link:label id="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E_label_en-US" xlink:label="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Exchangeable Common Units [Member]</link:label>
    <link:label id="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E_documentation_en-US" xlink:label="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Incremental weighted average common shares attributable to common units in the operating partnership that may be exchanged for common shares.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ExchangeableCommonUnitsMember" xlink:label="loc_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E" xlink:to="lab_ofc_ExchangeableCommonUnitsMember_81C8971EBE0EB62F68C38ED1DA99D51E" xlink:type="arc" />
    <link:label id="lab_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7_terseLabel_en-US" xlink:label="lab_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conversion of redeemable noncontrolling interests</link:label>
    <link:label id="lab_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7_label_en-US" xlink:label="lab_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Redeemable Noncontrolling Interest [Member]</link:label>
    <link:label id="lab_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7_documentation_en-US" xlink:label="lab_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Redeemable Noncontrolling Interest [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RedeemableNoncontrollingInterestMember" xlink:label="loc_ofc_RedeemableNoncontrollingInterestMember_D4375BABF73772BD27B08ED1DA9BD7F7" xlink:type="locator" />
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    <link:label id="lab_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F_terseLabel_en-US" xlink:label="lab_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Conversion of Series I preferred units</link:label>
    <link:label id="lab_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F_label_en-US" xlink:label="lab_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Series I Preferred Units [Member]</link:label>
    <link:label id="lab_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F_documentation_en-US" xlink:label="lab_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Series I preferred units representing ownership interest in the operating partnership.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_SeriesIPreferredUnitsMember" xlink:label="loc_ofc_SeriesIPreferredUnitsMember_53358BA5DF57C69029DF8ED1DA9B959F" xlink:type="locator" />
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    <link:label id="lab_ofc_ForwardEquitySaleAgreementMember_73FD7B309E25E3F35D738ED1DA9B0225_verboseLabel_en-US" xlink:label="lab_ofc_ForwardEquitySaleAgreementMember_73FD7B309E25E3F35D738ED1DA9B0225" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Weighted average shares related to forward equity sale agreements</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ForwardEquitySaleAgreementMember" xlink:label="loc_ofc_ForwardEquitySaleAgreementMember_73FD7B309E25E3F35D738ED1DA9B0225" xlink:type="locator" />
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    <link:label id="lab_ofc_RestrictedStockandDeferredSharesMember_53A098FF9107E2758FBE8ED1DA9B4BDE_terseLabel_en-US" xlink:label="lab_ofc_RestrictedStockandDeferredSharesMember_53A098FF9107E2758FBE8ED1DA9B4BDE" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted average restricted shares/units and deferred shares</link:label>
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    <link:label id="lab_ofc_RestrictedStockandDeferredSharesMember_53A098FF9107E2758FBE8ED1DA9B4BDE_documentation_en-US" xlink:label="lab_ofc_RestrictedStockandDeferredSharesMember_53A098FF9107E2758FBE8ED1DA9B4BDE" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Restricted Stock and Deferred Shares [Member]</link:label>
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    <link:label id="lab_us-gaap_EmployeeStockOptionMember_49A60C4B53E48D3A16948ED1DA9B7CC5_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeStockOptionMember_49A60C4B53E48D3A16948ED1DA9B7CC5" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Weighted average options</link:label>
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    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861_terseLabel_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earned PB-PIUs payout (as a percent of PB-PIUs granted) on 25th percentile rank</link:label>
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861_label_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award of Earned, Payout Percentage Based on Percentile Rank Equals to 25</link:label>
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861_documentation_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the earned payout, as a percentage of units granted, if the entity's total shareholder return relative to a peer group of companies ranks at the 25th percentile.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25" xlink:label="loc_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861" xlink:to="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankEqualsto25_E297EA0A0E48DAD4AD2F937BE87FD861" xlink:type="arc" />
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F_terseLabel_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Earned PB-PIUs granted on percentile rank below 25th (as a percent)</link:label>
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F_label_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award of Earned, Payout Percentage Based on Percentile Rank Less than 25</link:label>
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F_documentation_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the earned payout percentage based on percentile rank below 25.</link:label>
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    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F" xlink:to="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardofEarnedPayoutPercentageBasedonPercentileRankLessthan25_1CA16F8E7EA2CEEE30A5937BE87F3A0F" xlink:type="arc" />
    <link:label id="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E_terseLabel_en-US" xlink:label="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">The number of percentile ranks to fall between to earn interpolated PB-PIUs between such percentile ranks, conditioned on the percentile rank exceeding 25%</link:label>
    <link:label id="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E_label_en-US" xlink:label="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Number of Percentile Ranks to Fall Between to Earn Interpolated PSU</link:label>
    <link:label id="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E_documentation_en-US" xlink:label="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The number of percentile ranks to fall between to earn interpolated PSUs between such percentile ranks, conditioned on the percentile rank exceeding 25%.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu" xlink:label="loc_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E" xlink:to="lab_ofc_NumberOfPercentileRanksToFallBetweenToEarnInterpolatedPsu_BDD13623F3797EEC2F49937BE87F212E" xlink:type="arc" />
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Assumptions used to value stock awards</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_A8CA4630C3D59F5F231E937BE87F267F" xlink:type="arc" />
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A_terseLabel_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Percent of award distribution rights</link:label>
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A_label_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Distribution Rights as a Percentage of Non-PIU Common Units, Percentage</link:label>
    <link:label id="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A_documentation_en-US" xlink:label="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Distribution Rights as a Percentage of Non-PIU Common Units, Percentage</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage" xlink:label="loc_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A" xlink:to="lab_ofc_SharebasedCompensationArrangementbySharebasedPaymentAwardDistributionRightsasaPercentageofNonPIUCommonUnitsPercentage_240B426B7F9E9402013F937BE87FB45A" xlink:type="arc" />
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Award performance period</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_ED861AEAE0A70BC1EF33937BE880B8DD" xlink:type="arc" />
    <link:label id="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A_terseLabel_en-US" xlink:label="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Baseline value per common share (in dollars per share)</link:label>
    <link:label id="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A_label_en-US" xlink:label="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Baseline Common Share Value</link:label>
    <link:label id="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A_documentation_en-US" xlink:label="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the baseline common share value that is used in valuing the grant date fair value of awards.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue" xlink:label="loc_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A" xlink:to="lab_ofc_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsBaselineCommonShareValue_CC2CE6EFF29C113CDF0B937BE8802E3A" xlink:type="arc" />
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Expected volatility of common shares (as a percent)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_59C991FCB979B55A105D937BE880BFAA" xlink:type="arc" />
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_8AAD453EA35A1514FAE1937BE8801663_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_8AAD453EA35A1514FAE1937BE8801663" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Risk-free interest rate (as a percent)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_8AAD453EA35A1514FAE1937BE8801663_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_8AAD453EA35A1514FAE1937BE8801663" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_8AAD453EA35A1514FAE1937BE8801663" xlink:type="locator" />
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    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9A247E69C05A5FB654367AF751EE9FAF_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9A247E69C05A5FB654367AF751EE9FAF" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9A247E69C05A5FB654367AF751EE9FAF" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9A247E69C05A5FB654367AF751EE9FAF" xlink:to="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_9A247E69C05A5FB654367AF751EE9FAF" xlink:type="arc" />
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    <link:label id="lab_ofc_NorthernVirginiaMember_3A4A77D43C62F360CB2B7AF751F1D7C7_terseLabel_en-US" xlink:label="lab_ofc_NorthernVirginiaMember_3A4A77D43C62F360CB2B7AF751F1D7C7" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Northern Virginia Defense/IT</link:label>
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    <link:label id="lab_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D_label_en-US" xlink:label="lab_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenues from Real Estate Operations Received</link:label>
    <link:label id="lab_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D_documentation_en-US" xlink:label="lab_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash received for rents, tenant recoveries and other real estate operations during the current period.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_RevenuesFromRealEstateOperationsReceived" xlink:label="loc_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D" xlink:to="lab_ofc_RevenuesFromRealEstateOperationsReceived_9EC5A82B42BEEDFC1F858ED1DD3D4E5D" xlink:type="arc" />
    <link:label id="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0_terseLabel_en-US" xlink:label="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction contract and other service revenues received</link:label>
    <link:label id="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0_label_en-US" xlink:label="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction Contract and Other Service Revenues Received</link:label>
    <link:label id="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0_documentation_en-US" xlink:label="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash received for building and real estate development, which may include improvements (such as drainage, utilities, grading and subdividing) to a parcel of land, and general contracting services and from the sale of other goods or rendering of other services.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ConstructionContractAndOtherServiceRevenuesReceived" xlink:label="loc_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0" xlink:to="lab_ofc_ConstructionContractAndOtherServiceRevenuesReceived_89B082C82C4DF3E7F3E08ED1DD3D4BA0" xlink:type="arc" />
    <link:label id="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144_negatedLabel_en-US" xlink:label="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Property operating expenses paid</link:label>
    <link:label id="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144_label_en-US" xlink:label="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property Operating Expenses Paid</link:label>
    <link:label id="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144_documentation_en-US" xlink:label="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">This element represents the amount of cash paid during the current period for costs that are directly related to generation of revenues from leased and rented properties or equipment.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_PropertyOperatingExpensesPaid" xlink:label="loc_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144" xlink:to="lab_ofc_PropertyOperatingExpensesPaid_E550416B6538D4D1002F8ED1DD3D5144" xlink:type="arc" />
    <link:label id="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C_negatedLabel_en-US" xlink:label="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Construction contract and other service expenses paid</link:label>
    <link:label id="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C_label_en-US" xlink:label="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction Contract and Other Service Expenses Paid</link:label>
    <link:label id="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C_documentation_en-US" xlink:label="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash payments for costs related to construction and development services and other service operations during the current period.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ConstructionContractAndOtherServiceExpensesPaid" xlink:label="loc_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C" xlink:to="lab_ofc_ConstructionContractAndOtherServiceExpensesPaid_3FDC706C294434C702608ED1DD3EC99C" xlink:type="arc" />
    <link:label id="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24_negatedLabel_en-US" xlink:label="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">General, administrative, leasing, business development and land carry costs paid</link:label>
    <link:label id="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24_label_en-US" xlink:label="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">General and Administrative, Leasing, Business Development and Land Carry Paid</link:label>
    <link:label id="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24_documentation_en-US" xlink:label="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Cash payments for aggregate total costs related to selling a firm's product and services, all other general and administrative expenses, business development and land carry costs in connection with properties not in operations.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid" xlink:label="loc_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24" xlink:to="lab_ofc_GeneralandAdministrativeLeasingBusinessDevelopmentandLandCarryPaid_DE01CD26F9D74235DE408ED1DD3E2C24" xlink:type="arc" />
    <link:label id="lab_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Interest expense paid</link:label>
    <link:label id="lab_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27_label_en-US" xlink:label="lab_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Interest Paid, Excluding Capitalized Interest, Operating Activities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestPaidNet" xlink:label="loc_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27" xlink:to="lab_us-gaap_InterestPaidNet_25E74F56A121013A0E748ED1DD3E9D27" xlink:type="arc" />
    <link:label id="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F_negatedTerseLabel_en-US" xlink:label="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Lease incentives paid</link:label>
    <link:label id="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F_label_en-US" xlink:label="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments of Lease Incentives</link:label>
    <link:label id="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F_documentation_en-US" xlink:label="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Payments of Lease Incentives</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_PaymentsofLeaseIncentives" xlink:label="loc_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F" xlink:to="lab_ofc_PaymentsofLeaseIncentives_D4268D412251BA5C169D8ED1DD3E7A8F" xlink:type="arc" />
    <link:label id="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60_terseLabel_en-US" xlink:label="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60_label_en-US" xlink:label="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Operating Activities, Cash Flow Statement</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60" xlink:to="lab_us-gaap_OtherOperatingActivitiesCashFlowStatement_8462A72C1C97C95686808ED1DD3E4B60" xlink:type="arc" />
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net cash provided by operating activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_11A14276377D51441E358ED1DD3E2D2B" xlink:type="arc" />
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cash flows from investing activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_15BAA7C536C8478805F88ED1DD3F4723" xlink:type="arc" />
    <link:label id="lab_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Construction, development and redevelopment</link:label>
    <link:label id="lab_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F_label_en-US" xlink:label="lab_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments to Develop Real Estate Assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToDevelopRealEstateAssets" xlink:label="loc_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F" xlink:to="lab_us-gaap_PaymentsToDevelopRealEstateAssets_636D885B0922E7460B198ED1DD3F182F" xlink:type="arc" />
    <link:label id="lab_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xml:lang="en-US">Tenant improvements on operating properties</link:label>
    <link:label id="lab_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95_label_en-US" xlink:label="lab_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for Tenant Improvements</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsForTenantImprovements" xlink:label="loc_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95" xlink:to="lab_us-gaap_PaymentsForTenantImprovements_798D9C2CB2571364B0048ED1DD3F1E95" xlink:type="arc" />
    <link:label id="lab_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Other capital improvements on operating properties</link:label>
    <link:label id="lab_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F_label_en-US" xlink:label="lab_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Payments for Capital Improvements</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsForCapitalImprovements" xlink:label="loc_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F" xlink:to="lab_us-gaap_PaymentsForCapitalImprovements_BBEB05C1ED90AEE4AA378ED1DD3F739F" xlink:type="arc" />
    <link:label id="lab_us-gaap_PaymentsToAcquireNotesReceivable_21BDDEF6BA2A09FDEA178ED1DD3F14C4_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireNotesReceivable_21BDDEF6BA2A09FDEA178ED1DD3F14C4" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Investing receivables funded</link:label>
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    <link:label id="lab_us-gaap_GainLossOnSaleOfProperties_AB44373625FFA976B20A8ED1DD4577F9_label_en-US" xlink:label="lab_us-gaap_GainLossOnSaleOfProperties_AB44373625FFA976B20A8ED1DD4577F9" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Gain (Loss) on Sale of Properties</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensation_6CDBC734E3A6722173DA8ED1DD455DD4_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensation_6CDBC734E3A6722173DA8ED1DD455DD4" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Share-based Compensation</link:label>
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    <link:label id="lab_us-gaap_OtherNoncashIncomeExpense_8C3D68F4DBFB3165AA3C8ED1DD461263_negatedLabel_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense_8C3D68F4DBFB3165AA3C8ED1DD461263" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_OtherNoncashIncomeExpense_8C3D68F4DBFB3165AA3C8ED1DD461263_label_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense_8C3D68F4DBFB3165AA3C8ED1DD461263" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Other Noncash Income (Expense)</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_76ECE66BD8DCE1B3B6DB8ED1DD46615A" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_76ECE66BD8DCE1B3B6DB8ED1DD46615A" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_76ECE66BD8DCE1B3B6DB8ED1DD46615A" xlink:type="arc" />
    <link:label id="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_BDEC4731FFE76FA2DE4E8ED1DD4669CB_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_BDEC4731FFE76FA2DE4E8ED1DD4669CB" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">Decrease in accounts receivable</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_BDEC4731FFE76FA2DE4E8ED1DD4669CB" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_BDEC4731FFE76FA2DE4E8ED1DD4669CB" xlink:to="lab_us-gaap_IncreaseDecreaseInAccountsReceivable_BDEC4731FFE76FA2DE4E8ED1DD4669CB" xlink:type="arc" />
    <link:label id="lab_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C_negatedLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xml:lang="en-US">(Increase) decrease in prepaid expenses and other assets, net</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Prepaid Expense and Other Assets</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C" xlink:to="lab_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F2C7C3FD01183A1694248ED1DD46863C" xlink:type="arc" />
    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Increase (decrease) in accounts payable, accrued expenses and other liabilities</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Operating Liabilities</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B" xlink:to="lab_us-gaap_IncreaseDecreaseInOperatingLiabilities_235C76AD1EE0914DF9FE8ED1DD46DA6B" xlink:type="arc" />
    <link:label id="lab_ofc_IncreaseDecreaseInAdvanceRentAndSecurityDepositLiability_8E8DA585E8B2740AFF0A8ED1DD470110_terseLabel_en-US" xlink:label="lab_ofc_IncreaseDecreaseInAdvanceRentAndSecurityDepositLiability_8E8DA585E8B2740AFF0A8ED1DD470110" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">(Decrease) increase in rents received in advance and security deposits</link:label>
    <link:label id="lab_ofc_IncreaseDecreaseInAdvanceRentAndSecurityDepositLiability_8E8DA585E8B2740AFF0A8ED1DD470110_label_en-US" xlink:label="lab_ofc_IncreaseDecreaseInAdvanceRentAndSecurityDepositLiability_8E8DA585E8B2740AFF0A8ED1DD470110" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Increase (Decrease) in Advance Rent and Security Deposit Liability</link:label>
    <link:label id="lab_ofc_IncreaseDecreaseInAdvanceRentAndSecurityDepositLiability_8E8DA585E8B2740AFF0A8ED1DD470110_documentation_en-US" xlink:label="lab_ofc_IncreaseDecreaseInAdvanceRentAndSecurityDepositLiability_8E8DA585E8B2740AFF0A8ED1DD470110" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">The net change in amount that has been received by the entity that represents collections of cash or other assets related to real estate operations revenue for which revenue has not yet been recognized and security deposits.</link:label>
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    <link:label id="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperationsAbstract_4DDF0AE8CC5EC99EF4368ED1DD47B300_terseLabel_en-US" xlink:label="lab_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperationsAbstract_4DDF0AE8CC5EC99EF4368ED1DD47B300" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Reconciliation of cash and cash equivalents and restricted cash:</link:label>
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    <link:label id="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_F86736239C80AF6A34048ED1DD475573_verboseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsAtCarryingValue_F86736239C80AF6A34048ED1DD475573" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">Cash and cash equivalents</link:label>
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    <link:label id="lab_ofc_GuaranteedMaximumPriceMember_575F596AF3CBAF4592437442901A23C8_documentation_en-US" xlink:label="lab_ofc_GuaranteedMaximumPriceMember_575F596AF3CBAF4592437442901A23C8" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Guaranteed Maximum Price [Member]</link:label>
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    <link:label id="lab_us-gaap_FixedPriceContractMember_CB855C15BEB89C63559D7442901AA820_terseLabel_en-US" xlink:label="lab_us-gaap_FixedPriceContractMember_CB855C15BEB89C63559D7442901AA820" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Firm fixed price</link:label>
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    <link:label id="lab_ofc_CostplusFeeContractMember_6C44DB34CD1E7E27BEB07442901B2A28_terseLabel_en-US" xlink:label="lab_ofc_CostplusFeeContractMember_6C44DB34CD1E7E27BEB07442901B2A28" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Cost-plus fee</link:label>
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    <link:label id="lab_ofc_OtherServicesRevenueMember_BC63AF305D96F03E90AF7442901B0D05_terseLabel_en-US" xlink:label="lab_ofc_OtherServicesRevenueMember_BC63AF305D96F03E90AF7442901B0D05" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other</link:label>
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    <link:label id="lab_ofc_OtherServicesRevenueMember_BC63AF305D96F03E90AF7442901B0D05_documentation_en-US" xlink:label="lab_ofc_OtherServicesRevenueMember_BC63AF305D96F03E90AF7442901B0D05" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Other Services Revenue [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_OtherServicesRevenueMember" xlink:label="loc_ofc_OtherServicesRevenueMember_BC63AF305D96F03E90AF7442901B0D05" xlink:type="locator" />
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    <link:label id="lab_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A_terseLabel_en-US" xlink:label="lab_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Construction</link:label>
    <link:label id="lab_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A_label_en-US" xlink:label="lab_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction Service Revenue [Member]</link:label>
    <link:label id="lab_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A_documentation_en-US" xlink:label="lab_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents the construction service revenue from various groups.</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_ConstructionServiceRevenueMember" xlink:label="loc_ofc_ConstructionServiceRevenueMember_C97128F61F164A61E1787442901B124A" xlink:type="locator" />
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    <link:label id="lab_ofc_DesignServiceRevenueMember_BC504DA0E7D655064D707442901C44A8_terseLabel_en-US" xlink:label="lab_ofc_DesignServiceRevenueMember_BC504DA0E7D655064D707442901C44A8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Design</link:label>
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    <link:label id="lab_ofc_DesignServiceRevenueMember_BC504DA0E7D655064D707442901C44A8_documentation_en-US" xlink:label="lab_ofc_DesignServiceRevenueMember_BC504DA0E7D655064D707442901C44A8" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Design Service Revenue [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_DesignServiceRevenueMember" xlink:label="loc_ofc_DesignServiceRevenueMember_BC504DA0E7D655064D707442901C44A8" xlink:type="locator" />
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    <link:label id="lab_us-gaap_RevenuesAbstract_EFAA86F4297120F086838F66532A23DF_label_en-US" xlink:label="lab_us-gaap_RevenuesAbstract_EFAA86F4297120F086838F66532A23DF" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Revenues [Abstract]</link:label>
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    <link:label id="lab_us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_D703F9E7166EC18AEA848F66532A48BD_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_D703F9E7166EC18AEA848F66532A48BD" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lease revenue</link:label>
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    <link:label id="lab_srt_NameOfMajorCustomerDomain_8756E6B97E75BC58C71D7C2DBFECFABA_terseLabel_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain_8756E6B97E75BC58C71D7C2DBFECFABA" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Customer [Domain]</link:label>
    <link:label id="lab_srt_NameOfMajorCustomerDomain_8756E6B97E75BC58C71D7C2DBFECFABA_label_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain_8756E6B97E75BC58C71D7C2DBFECFABA" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Customer [Domain]</link:label>
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    <link:label id="lab_us-gaap_LessorLeaseDescriptionLineItems_BC74B2261188F21D8ECF7BE1DC0EC737_label_en-US" xlink:label="lab_us-gaap_LessorLeaseDescriptionLineItems_BC74B2261188F21D8ECF7BE1DC0EC737" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Lease, Description [Line Items]</link:label>
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    <link:label id="lab_us-gaap_LessorOperatingLeaseTermOfContract_C46500F49FFD4F1779DC7BE1DC0EC3AD_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeaseTermOfContract_C46500F49FFD4F1779DC7BE1DC0EC3AD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Term of Contract</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeaseTermOfContract" xlink:label="loc_us-gaap_LessorOperatingLeaseTermOfContract_C46500F49FFD4F1779DC7BE1DC0EC3AD" xlink:type="locator" />
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    <link:loc xlink:href="ofc-20190331.xsd#ofc_LessorOperatingLeaseAverageTermofContract" xlink:label="loc_ofc_LessorOperatingLeaseAverageTermofContract_D006BE05F36F87D155C17BE1DC0E5E93" xlink:type="locator" />
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    <link:label id="lab_us-gaap_LessorOperatingLeaseRenewalTerm_231F04832DD54D6F14BD7BE1DC0E7E6C_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeaseRenewalTerm_231F04832DD54D6F14BD7BE1DC0E7E6C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Renewal term</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeaseRenewalTerm" xlink:label="loc_us-gaap_LessorOperatingLeaseRenewalTerm_231F04832DD54D6F14BD7BE1DC0E7E6C" xlink:type="locator" />
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    <link:label id="lab_us-gaap_OperatingLeasePayments_BF07A0D51A1156166190560E15E2A347_label_en-US" xlink:label="lab_us-gaap_OperatingLeasePayments_BF07A0D51A1156166190560E15E2A347" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Payments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:label="loc_us-gaap_OperatingLeasePayments_BF07A0D51A1156166190560E15E2A347" xlink:type="locator" />
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    <link:label id="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability_C6469CC5A1960C4A456C560E15E3D1C2_label_en-US" xlink:label="lab_us-gaap_FinanceLeaseInterestPaymentOnLiability_C6469CC5A1960C4A456C560E15E3D1C2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Finance Lease, Interest Payment on Liability</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FinanceLeaseInterestPaymentOnLiability" xlink:label="loc_us-gaap_FinanceLeaseInterestPaymentOnLiability_C6469CC5A1960C4A456C560E15E3D1C2" xlink:type="locator" />
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FinanceLeasePrincipalPayments" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments_61C12CFBCF82A5F03637560E15E3B10B" xlink:type="locator" />
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    <link:label id="lab_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8_terseLabel_en-US" xlink:label="lab_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Huntsville, Alabama</link:label>
    <link:label id="lab_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8_label_en-US" xlink:label="lab_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Huntsville, Alabama [Member]</link:label>
    <link:label id="lab_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8_documentation_en-US" xlink:label="lab_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Huntsville, Alabama [Member]</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_HuntsvilleAlabamaMember" xlink:label="loc_ofc_HuntsvilleAlabamaMember_019DA96EF951187B90877E750FB6CED8" xlink:type="locator" />
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    <link:label id="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504_terseLabel_en-US" xlink:label="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Renewal term</link:label>
    <link:label id="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504_label_en-US" xlink:label="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Renewal Term</link:label>
    <link:label id="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504_documentation_en-US" xlink:label="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lessee, Lease Renewal Term</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_LesseeRenewalTerm" xlink:label="loc_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504" xlink:to="lab_ofc_LesseeRenewalTerm_C6105C97BE110476D7DE7E750FB81504" xlink:type="arc" />
    <link:label id="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8_terseLabel_en-US" xlink:label="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Number of contracts</link:label>
    <link:label id="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8_label_en-US" xlink:label="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Number Of Lease Contracts</link:label>
    <link:label id="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8_documentation_en-US" xlink:label="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lessee, Number Of Lease Contracts</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_LesseeNumberOfLeaseContracts" xlink:label="loc_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8" xlink:to="lab_ofc_LesseeNumberOfLeaseContracts_4410A534AB2AECB042CA7E750FB9CFB8" xlink:type="arc" />
    <link:label id="lab_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71_terseLabel_en-US" xlink:label="lab_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Remaining term of contract</link:label>
    <link:label id="lab_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71_label_en-US" xlink:label="lab_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Remaining Term of Contract</link:label>
    <link:label id="lab_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71_documentation_en-US" xlink:label="lab_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lessee, Remaining Term of Contract</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_LesseeRemainingTermofContract" xlink:label="loc_ofc_LesseeRemainingTermofContract_747055A84E1C6F1EFB757E750FB91A71" xlink:type="locator" />
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    <link:label id="lab_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2_terseLabel_en-US" xlink:label="lab_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lessee right-of-use asset</link:label>
    <link:label id="lab_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2_label_en-US" xlink:label="lab_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessee, Right-of-Use Asset</link:label>
    <link:label id="lab_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2_documentation_en-US" xlink:label="lab_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Lessee, Right-of-Use Asset</link:label>
    <link:loc xlink:href="ofc-20190331.xsd#ofc_LesseeRightofUseAsset" xlink:label="loc_ofc_LesseeRightofUseAsset_7423B774680DF136DF1A7E750FB91CF2" xlink:type="locator" />
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    <link:label id="lab_ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember_EACB9CE5086CEBB5E41B560E160237AD_terseLabel_en-US" xlink:label="lab_ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember_EACB9CE5086CEBB5E41B560E160237AD" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Projects in development or held for future development</link:label>
    <link:label id="lab_ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember_EACB9CE5086CEBB5E41B560E160237AD_label_en-US" xlink:label="lab_ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember_EACB9CE5086CEBB5E41B560E160237AD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Projects in Development or held-for-future Development [Member]</link:label>
    <link:label id="lab_ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember_EACB9CE5086CEBB5E41B560E160237AD_documentation_en-US" xlink:label="lab_ofc_ProjectsInDevelopmentOrHeldForFutureDevelopmentMember_EACB9CE5086CEBB5E41B560E160237AD" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Represents projects in development or held for future development.</link:label>
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    <link:label id="lab_us-gaap_ConstructionInProgressMember_C845A35504EBD317E466560E16042978_terseLabel_en-US" xlink:label="lab_us-gaap_ConstructionInProgressMember_C845A35504EBD317E466560E16042978" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Development in progress, excluding land</link:label>
    <link:label id="lab_us-gaap_ConstructionInProgressMember_C845A35504EBD317E466560E16042978_label_en-US" xlink:label="lab_us-gaap_ConstructionInProgressMember_C845A35504EBD317E466560E16042978" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Construction in Progress [Member]</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Properties</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Property, Plant and Equipment [Line Items]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentLineItems_4E4676AF02C33CF611AC560E16043045" xlink:type="arc" />
    <link:label id="lab_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fixed contractual payments</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Lease Income, Lease Payments</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLeaseIncomeLeasePayments" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C" xlink:to="lab_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_50A38019682D7DE982517BE1DC06DA0C" xlink:type="arc" />
    <link:label id="lab_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Variable lease payments</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Variable Lease Income</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseVariableLeaseIncome" xlink:label="loc_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B" xlink:to="lab_us-gaap_OperatingLeaseVariableLeaseIncome_0CF3570E287FC5054CAA7C310531414B" xlink:type="arc" />
    <link:label id="lab_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513_totalLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Lease revenue</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Operating Lease, Lease Income</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingLeaseLeaseIncome" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513" xlink:to="lab_us-gaap_OperatingLeaseLeaseIncome_D0870CF9393A3B07C3B57BE1DC075513" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Lease Payments to be Received</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract_1A5373455E082C1F2B007BE1DC072434" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear_4EC1EE45F1CFBF4C18357BE1DC076C31_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear_4EC1EE45F1CFBF4C18357BE1DC076C31" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2019</link:label>
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    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear_4EC1EE45F1CFBF4C18357BE1DC076C31" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear_4EC1EE45F1CFBF4C18357BE1DC076C31" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedRemainderOfFiscalYear_4EC1EE45F1CFBF4C18357BE1DC076C31" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2019</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received, Next Twelve Months</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths_5002C0019F639D031EFB7BE1DC073AED" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2020</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received, Two Years</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears_ABC8DBC66B1EE39D5D257BE1DC079BC9" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2021</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received, Three Years</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears_106C004EACF249369FB47BE1DC073DB2" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2022</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received, Four Years</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears_8AEB4F66370251C623207BE1DC0888D8" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">2023</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received, Five Years</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedFiveYears_FE07597BA96C328E54DB7BE1DC086835" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367_terseLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Thereafter</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received, Thereafter</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceivedThereafter_D664C7662CE87A7B4B237BE1DC083367" xlink:type="arc" />
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD_totalLabel_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Operating Lease Payments to be Received</link:label>
    <link:label id="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD_label_en-US" xlink:label="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Lessor, Operating Lease, Payments to be Received</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceived" xlink:label="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD" xlink:to="lab_us-gaap_LessorOperatingLeasePaymentsToBeReceived_DD45E51BA453A8CF4A6E7BE1DC08CCCD" xlink:type="arc" />
    <link:label id="lab_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping [Table]</link:label>
    <link:label id="lab_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75_label_en-US" xlink:label="lab_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping [Table]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75" xlink:type="locator" />
    <link:labelArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75" xlink:to="lab_us-gaap_FairValueByBalanceSheetGroupingTable_2DE7AF09DA5D1DC01011560E15937B75" xlink:type="arc" />
    <link:label id="lab_us-gaap_FairValueByMeasurementBasisAxis_159E1B61BE754AB00808560E1594B0FC_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByMeasurementBasisAxis_159E1B61BE754AB00808560E1594B0FC" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis]</link:label>
    <link:label id="lab_us-gaap_FairValueByMeasurementBasisAxis_159E1B61BE754AB00808560E1594B0FC_label_en-US" xlink:label="lab_us-gaap_FairValueByMeasurementBasisAxis_159E1B61BE754AB00808560E1594B0FC" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Basis [Axis]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_159E1B61BE754AB00808560E1594B0FC" xlink:type="locator" />
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    <link:label id="lab_us-gaap_FairValueDisclosureItemAmountsDomain_7BF8A21C9653BDC1A8E1560E15946C3F_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueDisclosureItemAmountsDomain_7BF8A21C9653BDC1A8E1560E15946C3F" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Measurement [Domain]</link:label>
    <link:label id="lab_us-gaap_FairValueDisclosureItemAmountsDomain_7BF8A21C9653BDC1A8E1560E15946C3F_label_en-US" xlink:label="lab_us-gaap_FairValueDisclosureItemAmountsDomain_7BF8A21C9653BDC1A8E1560E15946C3F" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Measurement [Domain]</link:label>
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_7BF8A21C9653BDC1A8E1560E15946C3F" xlink:type="locator" />
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    <link:label id="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember_BC0E14D9E3F71564761B560E15948E2C_terseLabel_en-US" xlink:label="lab_us-gaap_CarryingReportedAmountFairValueDisclosureMember_BC0E14D9E3F71564761B560E15948E2C" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Carrying Amount</link:label>
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    <link:label id="lab_ofc_OtherFixedRateDebtMember_ABD22B1E1C2D426CD399560E159582EE_terseLabel_en-US" xlink:label="lab_ofc_OtherFixedRateDebtMember_ABD22B1E1C2D426CD399560E159582EE" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Other fixed-rate debt</link:label>
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    <link:label id="lab_ofc_FurnitureFixturesandEquipmentNetMember_8AA8395BF1430FC19D867E750F4AC289_terseLabel_en-US" xlink:label="lab_ofc_FurnitureFixturesandEquipmentNetMember_8AA8395BF1430FC19D867E750F4AC289" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Furniture, Fixtures and Equipment, Net</link:label>
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