It's nice that the wiki entry for wardrobe_error includes a lot of related tags, but I'm still surprised that wardrobe_error isn't an implication whenever those tags are used. The panties_on_head tag, for instance, when added to an image doesn't automatically include the wardrobe_error tag like it should. Someone should fix this soon.

On a small note, I know that the asshat tag refers to a hat being worn on the buttocks, but the word asshat was also often used to refer to the silly heart-shaped hat used on an episode of Code Geass R2 (due to the fact that it looked like a pair of buttocks when seen from above). What would be a good tag for that hat--cupid_day_hat maybe?

If there are tags you think should implicate wardrobe_error you should just include them in your OP, rather than have everyone else dig up the wiki just to see what you mean. That's the typical format for these things. Also, for the second topic, it'd be nice if you included any existing relevant images on Danbooru in your post.

Asshat to me seems like a lousy name for a tag to begin with since it primarily refers to an insult. It should probably just be edited (since it only has 10 images) to hat_on_ass, which is more immediately understandable and easy to guess.

It still shouldn't be used just for a joke reference, though. I haven't really watched the show but whatever the tag is called, it should be as "official" as possible. If the tag is even needed, anyway. A quick search of code_geass hat only brings up a handful of relevant images, (post #469285, post #351173, post #274397) but it's a unique enough hat, I guess.