If you enable tagging with Use track relationships, you get these extra variables:
Variables will not be created if there was no value retrieved for the variable from the MusicBrainz database.
The sort names of the lyricists for the work. (since Picard 2.9)
List of performance attributes for the work (e.g.: “live”, “cover”, “medley”). Use $inmulti to check for a specific type (i.e.:
$if($inmulti(%_performance_attributes%,medley), (Medley),)). (since Picard 1.3)
Recording disambiguation comment. (since Picard 0.15)
Recording title - normally the same as the Track title, but can be different.
Work disambiguation comment. (since Picard 2.7)
The sort names of the writers for the work. (since Picard 2.9)