Is Double_chin valid? there's no wiki page for it.

Yes.
There is now: gelbooru.com/index.php?page=wiki&s=view&id=20420

Artist Names:
shimuni -> uraraku_shimuni
ichinose_ya_hiro -> ichinose_yahiro

If Im wrong, tell me why :)

Does "1boy" apply to human males only, or to everything male? Animals, pokemon, monsters, aliens...
NSFW example: gelbooru.com/index.php?page=post&s=view&id=2265047

1boy can apply to anything with an apparent or cannon male gender, even animals/furries.

Note:Only in the English sense. A book might be male in Spanish but only personified inanimate objects may be tagged 1boy.

This does not apply to tags like loli and shota. The character must be human-like and not animal-like to get a loli or shota tag.



Shimuni is an ambiguous tag.
Ichinose_ya_hiro is incorrectly Romenised.

Yep, Thx for tellme (for ensure), for those inconsistencies I was requesting update both tags. If I find more, I'll post here.

A lot of pictures are being/have been added with the bondage tag without even having anything bondage-ish shown.

What about Pokemon tag? originally is with "accent mark" Pokémon.

All tags must be typeable with a standard US-English keyboard without alt codes or an IME. This means that accent marks are not allowed in tags.

Saw those and removed the tag.