Field help (DPRDURG) @ L.V. Expertise X3

The rules for the entry and the value of the depreciation duration are a function of the depreciation method entered:

The duration can be entered except if the method has the value: WD (With depreciation), OU (Operation units), PI (Inflated progressive), OR (Ordinario), AN (Anticipato) or IT (Ordinario/Anticipato).
In this case, the duration will be equal to 0 and it cannot be modified.
If the mode has FM for value (Shapes and moulds), the duration is automatically of 3 years.
If the mode has LG for value(Line), the duration is automatically of 1.5 year.
If the mode has LP for value (French straight-line), and the specific rule is 12 months software, the duration is automatically of 1 year.
It is mandatory that it is greater than or equal to 3 years for the Digressive type methods.
If the depreciation method is a Free, method, the duration is at least equal to the minimum duration specified for this method.