At present, we have documentation for:

title: guess case, etc.
artist: the detailed artist credit bubble
packaging: packaging types list documentation
barcode: what to do about none, validation
annotation: explain what it is, that it has wiki-like syntax
disambiguation: explain what it is, what stuff should actually go in the annotation

I'd propose we add some more, perhaps including some of:
language, script: these are only for the tracklist, which is a frequent source of confusion for folks
status: pseudo-release is rather... unknown, and I'm sure we can do better for the rest too
country: I'm sure we can find something useful to talk about here with respect to digital releases, and those released in multiple countries
label: note that labels are imprints, link documentation on how to determine the appropriate label. perhaps also something about catalog number formatting? unsure
type: I'm sure we can at least link some documentation here (do we have anything about common combinations of types and what they mean?)