In Poland we need to keep evidence of tax depreciation for fixed assets. The method for depreciation which is the most appropriate from legislation point of view is Straight line percentage (Poland). However tax depreciation is not required to be booked to General ledger and the best way would be to use posting layer None instead of any other layers for this purposes. Unfortunately currently for several depreciation methods like: Straight line percentage (Poland), Straight line (Poland) is not possible to use layer None.