The characters Feo_Ul and Titania, and subsequently any other pixies from the game Final Fantasy XIV (there will probably be art of An Lad at some point), are canonically genderless and are all referred as such. Most give off a kind of feminine appearance but giving them tags like "1girl" doesn't seem accurate to use. I don't know if you have some ruling to a situation where the artist takes liberties and gives them breasts or some such though.

If they appear genderless or could reasonably pass as such, tag them as others (1other, 2others, etc).

If the artist took some liberties and made them obviously female or male, tag them as girls or boys. What counts as “obviously” is left to the discretion of the tagger and may or may not cause heated discussions in the comments. ;-) In this case, do not tag them as genderswap since they have no gender to swap.

Some prior cases: Frisk and Chara from Undertale and the gems from Houseki no Kuni.

Been meaning to ask about how to deal with our beautiful branch.

That should be the posts fixed, I'll write up wikis in the morning.

Edit: wikis are done. non-spoiler examples have been given for Titania.