One of the important features of screens is that they can provide users with lists of possible entries for a field. There are three techniques that you can use to create and display input help:

1. Definition in the ABAP Dictionary

In the ABAP Dictionary, you can link search helps to fields. When you create screen fields with reference to ABAP Dictionary fields, the corresponding search helps are then automatically available. If a field has no search help, the ABAP Dictionary still offers the contents of a check table, the fixed values of the underlying domain, or static calendar or clock help.

2. Definition on a screen

You can use the input checks of the screen flow logic, or link search helps from the ABAP Dictionary to individual screen fields.

3. Definition in dialog modules

These three techniques are listed in order of ascending priority. If you use more than one technique at the same time, the POV module calls override any definition on the screen, which, in turn, overrides the link from the ABAP Dictionary.

However, the order of preference for these techniques should be the order listed above. You should, wherever possible, use a search help from the ABAP Dictionary, and only use dialog modules when there is really no alternative. In particular, you should consider using a search help exit to enhance a search help before writing your own dialog modules.