ABAP Keyword Documentation → ABAP − Reference → SAP GUI User Dialogs → General Dynpros → Field Help, Input Help, and Dropdown List Boxes
Dynpros use input helps to support interactive input. This can be done in three different ways.
These three options are ordered by priority. If you use more than one technique at the same time, the POV module calls override any definition on the dynpro, which in turn overrides the binding to ABAP Dictionary.
These three options should, however, be applied in the given order. If possible, a search help from ABAP Dictionary should always be defined for the input help and input help should only be defined in dialog modules if no other option is available. In particular, you should consider using a search help exit to enhance a search help before writing your own dialog modules.
7.31 | 7.40 | 7.54
Input Helps from ABAP Dictionary