I want to discuss two character tags that currently exist, but I have an idea to improve their posts with a new tag. The two current tags are jasmine_(nanimoose) and jaz. These are both character tags. The posts in question are Jaz by artist Nanimoose. If you search for Nanimoose, some posts of Jaz (purple wolf) are not character tagged. Of course, this can be easily fixed by adding the tags, but there are two options.

I just talked to the artist, Nanimoose, and he said that he changed her name to Jaz because Jasmine was too common. Since her character tag is jasmine_(nanimoose) and there are other posts not by Nanimoose with the Jaz character tag, could it be renamed to jaz_(nanimoose)? Sorry to ask, but is it even possible to rename a tag without entirely replacing it with all its posts?

Just so there's no confusion, jasmine_(nanimoose) to jaz_(nanimoose).

It's very possible. It sounds like jaz_(nanimoose) is now the more accurate tag for that character. And since it's also what the artist would prefer, it sounds like a good plan to do.

To answer your question, what's possible is to create a new tag with the desired name (jaz_(nanimoose)), and then move the images that belong to it manually by editing each one to remove the old tag and add the new one. That way any images which don't fit (other characters with the same name) aren't affected, but all of nanimoose's character ends up with the corrected tag. So that's what will have to happen with the images that weren't already tagged with jasmine_(nanimoose).

Since it sounds like jaz_(nanimoose) should be her official tag now, I used an alias (it's an admin tool) to move all of the images that were already tagged with jasmine_(nanimoose) to become --> jaz_(nanimoose). That way those at least won't have to be moved manually, and the site will automatically fix it if someone tries to tag it as jasmine_(nanimoose) in the future without realising the name has been changed to jaz_(nanimoose). The site will change it for them because of the alias I just made for it.

So that takes most of the work out of it. But any images of Nanimoose's character that were under the regular jaz or jasmine tag will have to be moved manually to the jaz_(nanimoose).