ID

Anime

aid = short for anime ID
Every anime in the DB has exactly 1(!) unique ID.

Creq

cid = short for creq ID
Every creq in the DB has exactly 1(!) unique ID, which makes it possible to track down every change done.

Episode

eid = short for episode ID
Every episode in the DB has exactly 1(!) unique ID.

File

fid = short for file ID
Every file in the DB has exactly 1(!) unique ID.

Group

gid = short for group ID
Every group in the DB has exactly 1(!) unique ID.

Groups also have an agid = short for anime group id
This id is unique for each anime+group combination and is used for anime group ratings and other anime+group related stuff.

Producer

prid = short for producer ID
Every producer (company) in the DB has exactly 1(!) unique ID.

Review

rid = short for review ID

User

uid = short for user ID