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28. OPERATING COSTS AND EXPENSES (Details 3) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure Of Operating Provisions Reversals [line items] |  |  |  |
Estimated losses on doubtful accounts receivables | [1] | R$ 147 | R$ 238 | R$ 264
Estimated losses on other accounts receivables | [2] |  | 11 | (4)
Estimated losses on accounts receivables from related parties | [3] | 37 | 688 |
Contingency provisions (reversals) |  |  |  |
Labor claims | [4] | 46 | 136 | 42
Civil | [4] | 43 | 24 | 13
Tax | [4],[5] | 75 | 1,228 | (5)
Other | [4] | 22 | 12 | 1
Other provisions | [4] | 186 | 1,400 | 51
Operating provision (Reversals) | [4] | 370 | 2,337 | 311
Adjustment for losses |  |  |  |
Provision for losses |  | 53 | 64 | 155
Operating provision (reversals) and adjustment for losses , Total |  | 423 | 2,401 | 466
Written put options [member] | RME and LEPSA [member] |  |  |  |
Adjustment for losses |  |  |  |
Provision for losses |  |  |  | 48
Written put options [member] | S A A G lnvestimentos S A [member] |  |  |  |
Adjustment for losses |  |  |  |
Provision for losses |  | R$ 53 | R$ 64 | R$ 107
[1] | The expected losses on receivables are presented as selling expenses in the Statement of Income.
[2] | The estimated losses on other accounts receivable are presented in the consolidated Statement of income as operating expenses.
[3] | Estimated losses on accounts receivable from Renova, as a result of the assessment of the jointly-controlled entity credit risk.
[4] | The provisions for contingencies of the holding company are presented in the consolidated statement of income for the year as operating expenses.
[5] | The provision recognized in 2019 is due to the Company's reassessment, based on the opinion of its legal advisers, of the probability of loss in legal actions disputing social security contributions on the payments of profit-sharing to its employees from 1999 to 2016. For more information, see note 25.

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