If the current MIDI document contains a copyright notice then the copyright is displayed (the info is also displayed in the document window).
Copyright: (c) 1990 Die Toten Hosen
If no copyright command is in the file then the operation allows to enter a new copyright text. The new copyright notice is added to first track.
It is not possible to modify an existing copyright with this operation!
Legal notice:
Add copyright only if you are owner of copyright, i.e. you are composer of the song or you have licensed the distribution rights for this song from the copyright owner.