-: negative
+: positive
+/-, or ~: both negative and positive in some ways
mh: mental health
ph: physical health
what: if you read it, you'll say "what (the fuck)"
ec: eye contact
meta: related to fedi itself, like the spam problem could be considered a meta topic
uspol, ukpol, depol, ...: politics for the respective country code
ment: mention of something (for example, transphobia ment means a mention of transphobia)
oh: overheard, it's posting something someone else said sans context
subpost, subtoot, sub(other posting word): essentially vagueposting about something someone said or did without directly @'ing them in the post (tends to not mention the person by name either, if they have a chance of seeing it)
sh - self harm
sui - suicide
alc - alcohol
(also non-new people if you can think of any more, please suggest and i will add!)