I was trying to register a taxonomy for the Media page and checking the register_taxonomy function in the codex, I found this:
WordPress builtin post types:
I thought using 'mediapage' as the second argument of the register_taxonomy function ($object_type) would put my taxonomy under the Media item in the menu, but no.
I guess I can register this taxonomy anyway and add some custom fields to the media upload page, but if this can somehow work automatically I'd like to know. I'd prefer to use the normal WordPress category select box instead of building my own for instance.
Further more, I found no mention of 'mediapage' anywhere in the files, so I don't know how this can be a builtin post type.
If anyone has a clue, I'd appreciate it.