Suppose you have a simple script like this:
$set(DISPLAY ARTIST,%artist%)
(note the use of capitals)
Using that, on a first run Picard will show ‘DISPLAY ARTIST’ in the first column of the bottom pane.
But when you save the result, and then scan the release again, it will display a populated ‘display artist’ (lower case), and add a second line with a blank ‘DISPLAY ARTIST’ that it offers to populate.
So you now have two display artists in the left column.
Is this expected behaviour?
edit:
This concerns flac files, mp3 seems to have no problem.