According to Database Structure · ankidroid/Anki-Android Wiki · GitHub there is/was a field named “tags” in notetype.
It’s set in AnkiDroid in Anki-Android/AnkiDroid/src/main/java/com/ichi2/anki/NoteEditor.kt at 0de2eb08b2ff5acfc597564bde65edc2c7f58864 · ankidroid/Anki-Android · GitHub
As far as I can tell, this value is never read anywhere in anki or ankidroid.
Which is probably great, because right now, ankidroid seems to store garbage in it (it puts an object instead of a string)
Am I right in understanding that it’s a old property that is now unused?
I hesitated, because I see that in note type there can be a special field named “Tags”.
anki/rslib/src/notetype/mod.rs at 63c2a09ef6760890c03be4bd83f613c03c512d1f · ankitects/anki · GitHub and that it get sets in anki/rslib/src/notetype/render.rs at 63c2a09ef6760890c03be4bd83f613c03c512d1f · ankitects/anki · GitHub
but I think this is about the note’s fields, and not actually the notetype’s field.