Field help (DPRRAT1) 

The value of the depreciation rate when applying associations.
If the Rate section has been defined as "managed" for the plan, then the information remains optional.
In the case where the method entered is SA (without depreciation) or UO (Work unit), this field cannot be entered, as the rate must be equal to 0.
In the DF French declining mode, this field cannot be entered, as the rate is automatically calculated based on the duration.