dfy6c said:
This is true. There was even a BUR attempt to make crossgender a lore tag on e621 to the point that it was even accepted, but then it didn't change because of this. You can see here and here. This is the code that forces you to have _(lore) at the end of the tag for the category to work.

If crossgender is to be a lore tag, it MUST have _(lore) at the end of it.

Crossgender_(lore) itself could be a lore tag, though it's the other ones that I'm hung up on, like mtf_, fta_, etc. The "f" in mtf is something that is TWYS because that is what is in the image, which probably makes those general tags, but at the same time, the whole point of the tag in the first place is because of outside knowledge. It's kinda tricky because it has elements of both Tag What You Know and Tag What You See. In that e621 thread, they started leaning on the idea of keeping "mtf_" and the rest as general tags, with crossgender_(lore) being the base lore tag.

Personally, I'll say yes to the first two lines here for part 1 (the rest are just category changes so not really a big deal here), but I'm kinda eh on part 2.

Like I said earlier, the lore tags will only deal with the "From" Gender. Using your own example, mtf_crossgender. The "Male" part of the tag is TWYK. The "Female" part is still TWYS, since that is what would be on screen.

The tag is both TWYS and YWYK, yes, but it's easily dealt with in the way I described. The "From" gender will be the lore tag and the "To" gender would be the general tag. It's an easy fix.