Field help (KACLCOEDG) 

The depreciation accelerator coefficient is used to manage depreciation modes: Declining balance, Belgian declining, Russian straight-line, Russian declining, Russian constant and Softy Russian modes. It can only be modified for these depreciation modes.
When this factor is applied to the Belgian declining mode, it must be included between 1 and 2 and contain up to 2 decimals (examples: value 2 corresponds to 200 %; the value 1.5 corresponds to 150 %).