Thank you both for your reaction.
@ JPA, My scenario is just like the screen shots of Camilo Antonio but with the RV document type.
In FAGLL03 I select an item, choose change mode and change the text (position text BSEG-SGTXT). But when saving, the field value changes back to its original text. The message "No changes made" is shown under in the screen.
@ Camilo Antonio, I implemented the note, but without any result.
Any more ideas would be appriciated.
Best regards,
Jorgen