Convert In-franchise crossovers to a tag

BUR #14272 has been approved by @evazion.

mass update pool:5784 -> in-franchise_crossover -pool:5784

This is a well defined topic that seems perfectly appropriate for a tag, rather than being an extremely underused pool. There's currently no way to search for crossovers between multiple different installments in big franchises like Gundam or Precure without trying out each combination one at a time. The only points of debate I can see regarding it's usage as a tag would be the following:

• Art from official in-franchise crossover works (eg. Dissidia Final Fantasy and Fire Emblem Heroes). I personally wouldn't exclude them (a piece of in-franchise crossover art doesn't stop being one because it's official), but I could see some contention against their inclusion. On the other side I'm not sure these sorts of copyrights would flood the tag, or if people looking for this kind of art would mind. Obviously these would only be for art from those works that actually feature a crossover and not just official alternate costumes.

• Copyrights that are in the same setting/continuity/universe but are treated as separate entities on danbooru. This would include combinations like Nier/Drakengard and Apex Legends/Titanfall, as well as bigger messes like Megami Tensei and all of it's offshoots (Persona, Digital Devil Saga, etc) or the MuvLuv/KimiNozo/KimiIta trio (separate works within the same setting/continuity with some recurring characters)

• Cosplay. Simple cosplay like post #5789752 typically doesn't qualify for the regular crossover tag, would we keep that convention for in-franchise crossovers?

In the meantime I'll work on making some favgroups for the franchises I'm familiar with (mostly Gundam, Macross, and Transformers) and put those up to a BUR if this one goes through.

The bulk update request #14272 (forum #229833) has been approved by @evazion.

The bulk update request #14272 (forum #229833) has been approved by @evazion.

Is this tag only for non-canonical crossovers (as the wiki currently states)? Does that mean it can't be used for, say, Precure, because all Precure series canonically take place in the same continuity? Can it not be used for Digimon, because of that one crossover Hunters episode?

The_Bob said:

Is this tag only for non-canonical crossovers (as the wiki currently states)? Does that mean it can't be used for, say, Precure, because all Precure series canonically take place in the same continuity? Can it not be used for Digimon, because of that one crossover Hunters episode?

Personally I think that should be changed as well, because official crossover works within franchises are a thing and usually involve dimension jumping or time travel shenanigans to make characters meet who otherwise weren't (or they're purely for promotional reasons like post #3622377). post #2877529 for example is a piece of official art from an official crossover work, but it doesn't change the fact that it's still an in-franchise crossover between characters from different installments.

How do you define the tag in a way that it doesn't include every Fate or Touhou post? There are certain games that are either designed to be massive in-franchise crossover fests (see: Fate/Grand Order, Fire Emblem Heroes, Super Smash Bros., etc), or where in-franchise crossovers are so common that people don't recognize them as crossovers (see: Touhou characters from different games being drawn together).

Touhou doesn't count for this since all the games are a single linear series (although a case could be made for the PC-98 games since those are their own continuity). Fate could be excluded using a similar logic for excluding series like Kantai Collection from the personification tag: it would drown out the lesser results which are what people want to use the tag to find.