This has been weighing on my mind for a while now. What is and isn't acceptable to add as Extra Title Information (ETI)? I know Guess Case automatically removes "bonus track" but there are others it misses, and the current ETI style guideline is not totally clear on this.
Related ticket: STYLE-777
Related discussion: https://community.metabrainz.org/t/itunes-track-titles/274548