This is an attempt to make sense out of the categories that I have been imposing. I've mainly been doing it by heart and now find myself tripping up.
Countries are areas with a clearly defined group of population. I've avoided State because that implies a level of sophistication which sounds alien to a large number of countries - c.f. Sartar. Countries should receive a locational category (ie Pelorian) and a cultural category (ie Dara Happan).
Cultures: I'm aiming for a broad brush here. Logical Cultures include the Malkioni and Zzaburi. Orlanthi cultures the Heortlings and those related to the Orlanth-worshipping cultures (ie the Caladrans), Beastfolk (ie Centaurs and Satyrs), Praxians (Five Greats, Ten Independents and Oasis Folk), Hyalorings (Pentan horse riders). The Lodrili refers to the native people of Peloria
Deities receive a cultural category, a type category (ie gods, spirits), a power category (one, two or three runes) and a specialization category (war, healing etc). Some of those categories are going to be large.
Inhumans are being grouped according to the Inhuman Schemes
State: See Countries
Tribe: has been used in several ways i) to identify a mobile population or a minority scattered over a large area (ie the Telmori Tribe), ii) to identify a tribe that self-identifies as a Tribe (ie the Colymar). The first should be avoided.
Many details are being worked out on pages such as the Culture sandbox