Created attachment 2406 [details] gtk2-de.po-use-better-word-for-signing-button.patch The term "Unterzeichnen" usually refers to the act of signing something physically, with a pencil. Use the same term which is used for the menu entry, which is typically used when signing in a digital context.
Created attachment 2407 [details] master-de.po-use-better-word-for-signing-button.patch
Normally I would suggest contacting the translator directly so that when an update is submitted for the next release your suggestion can be incorporated. However, the project is lacking a German translator for a number of releases and years now. Eventually this will result in the German translation being dropped.