Sort fields are not stored in ID3-Tag (v2.3)

Nothing.

Because it isn't an ID3 tag field. It's unique to iTunes.

Regardless of whether they are "official" fields or not, iTunes does store the sort fields in the tags. If they are not being recognised after delete & reimport then the probable cause is multiple tags which iTunes doesn't handle well.

tt2

P.S. Not sure what internal field names iTunes uses but ID3v2.4 proposes:
~ TSOA Album sort order (Sort Album)
~ TSOP Performer sort order (Sort Artist)
~ TSOT Title sort order (Sort Name)
though the tags I've tested are v2.3 and work just fine.

P.P.S. A quick play with the newly discovered (at least by me) ID3 Raw Tag Viewer confirms the above and also:
~ TSO2 Sort Album Artist
~ TSOC Sort Composer

Presumably iTunes uses something similar in AAC tags.

Message was edited by: turingtest2

Good information! Thanks, tt. I will defer to your expertise in this matter. You are the guru of tagging!

🙂

Going back to the orignal post, many tag editors only show a selection of fields which may be where the confusion lies... If you can't see it, you assume it isn't there.

tt2