SELTEXT is one of the fields that are linked to the texts of the grid columns. This particular one is responsible for displaying the name of the column in the change/display of layout popup. ...
... then if you explicitly don’t set the SELTEXT and TOOLTIP fields, ALV will automatically copy the content of REPTEXT into those fields.
Figure 98 Field catalog with automatic and manual REPTEXT ...
... very helpful for explaining the user the meaning of the column.
Figure 81 ZDEMO_AIN_CL34 Tooltip of an column
Additionally if you’ll not use SELTEXT field, then the value ...