How should this be handled?
As per https://e621.net/wiki/show?title=e621%3Atag_what_you_see_%28explained%29 , "TWYS says that all tags on a post must be directly verifiable within the post itself. Example: a solo picture of what APPEARS to be a male character will be tagged "male". Even if the character was defined as "female" on other sites by the artist or character owner themselves, the picture would still need to be tagged "male" on e621, because of the TWYS policy."
This being said, crossgender seems to be for most intents and purposes as an irrelevant tag on perhaps several levels.
As in the example, outside info such as the owner stating 'My OC is usually male' is irrelevant. So for any potential 'crossgender' picture, this is irrelevant too. You would just tag it as you see depicted in the specific picture regardless. Thus crossgender is not an appropriate tag.
For characters from other franchises, such as say... Bowser from Mario bros, or Fox from Star Fox, is this somehow different from the above example? Is this different than the OC-owner stating an established gender when the owner is a company? One could argue 'This is how the character is typically depicted in all the games', but that's not really different than with the OC-owner example above either and is also arguably not TWYS.
So it would seem then that the only proper use of crossgender is when one instance of the character is depicted within the same image as differently gendered than another same-image instance of the same character. Which is kind of oddly niche.
Obviously something useful IS conveyed in the 'crossgender' tag, but it also seems to tie into the unfortunate consequences part of TWYS and by the rule should be left out.
So what's the call on this? Sorry for the long winded post, and thanks for your time.
Updated by TheHuskyK9