Ever since the creation of the TV db there has really a distinct lack of guidance for it's content along with some missing implementations. One area where it has gotten especially noticeable for me is "Anime" - aka the cartoons from Japan. With one of the mods recently quitting that wanted to help in that area I think it is about time to tackle the issues. Now don't get me wrong, I do not want any "special" treatment for this type of content per se but guidelines addressing the issues that come up when entering it here. Currently it's just random depending on who is entering stuff (which is at a low standard for anime anyways) and I mostly limit myself to just clean up a little once it affects me (via trakt).
See some discussion points below. I didn't feel like writing it all out again so I linked some threads there. I'm sure there are things I forgot about just now.
Shows vs Productions Anime is usually aired in cours, which is a three-month long television season. Sequels and the like always get a new title for a cour and can have completely different staff and studios behind them (along with production committees, etc.). For those reasons you find the entries in anime specific databases separate to each other. Western sites do however treat them as a main show with seasons (tvdb, tvrage, etc.). Going by the discussions linked below it was never established as to how TMDB wants to go along with it. At the moment you can find single seasons in the DB however most shows are "westernized" given the db dump...
Anime production? (http://www.animenewsnetwork.com/feature/2012-03-05 / https://washiblog.wordpress.com/2011/01/18/anime-production-detailed-guide-to-how-anime-is-made-and-the-talent-behind-it/ / https://www.youtube.com/watch?v=6wMqH0sJ-zE)
➥ Easy decision to make. Either separate them and clean up all existing data or keep them as it is (season titles help here).
Absolute numbers I'm sure you encountered this more than enough. Certain shows are just continuing on like One Piece. TVDB, Wikipedia, etc. do arc splits for them; TMDB has also taken over this practice (unofficially). Unlike TVDB you do not however not carry absolute numbers. So in case of One Piece the first episode of Season 16 is number 632 (or smth) in your DB... certainly doesn't make sense. Then there are other shows like Gintama that get released on streaming sites per absolute numbers but actually carry cour titles which anime dbs separate for the numbering (http://thexem.de/xem/show/305).
➥ Decide on arc splits, deal properly with absolute numbers.
Split cour In recent years we saw more "split cours", aka shows that get their second half with a season gap in between. TVDB has decided to merge them together, anime dbs do however split them. A good example for this would be Durarara with three separate cours for season two (x2: Shou, Ten and Ketsu).
➥ Do you want to merge split cours? You'll find both practices in the db...
https://www.themoviedb.org/talk/54bd63bdc3a3681421007ede (here is me getting it done the old tvdb way... s1 is a mess)
OVAs etc OVAs are disc releases of anime. TVDB for example does not allow them in their DB unless they can be paired with a show. They can be standalone series (only 2-3 episodes long) but also unaired episodes for tv shows. In plenty of cases when they're unaired episodes they're not bundled with the shows actual disc release but for example their original manga. It goes so far that those episodes then get labeled as say "Episode 14". The TV section also needs the adult tag for hentai content (last example)
➥ Are they welcomed in the DB? Where do you put standalones (movie, shows)? Can they become an additional season of a show? Can they be part of a season`that aired on TV?
Rebroadcasts Apparently there are no rules as to how to deal with edited rebroadcasts of shows in the US. At least it looks like that.
➥ I mean this is easy for me... Just don't allow those entries like recuts of movies etc.
Various luckily we're getting rid of mini-series https://www.themoviedb.org/talk/56aca3e9c3a3681c340054d5...
Things that will also greatly help here: