Tags for deletion

I don't see anything related in the first forum pages nor in the Useful Threads Index (sorry if I missed it). There's no thread for deleting unused/unwanted tags?

Like zettai_rouiki is just a mispelling of zettai_ryouiki. Once the post having the tag has been corrected, and the tag has 0 posts, does it get deleted after a while, or on certain tag cleanup moments?

I catched these three tags and corrected the posts to have the correct tags, and now the tags have no posts and should be deleted, so if there's a better way to ask for it, please enlighten me. I'm willing to learn so I can contribute more to Danbooru.

zettai_rouiki
_(kantai_collection)
_kennedy_(cv-67)

Unless someone's gone and made a wiki page for them or something you can just leave them.

Tags don't get pruned (since 2013). They are just left as is.

IIRC empty tags are kept on purpose so that the tag type (character/copyright/artist/general) isn't lost. This makes a difference when looking at post edit histories; if empty tags were deleted, then you wouldn't be able to tell what the tag type was for those tags in the edit history.