Why is invalid_tag tagged on so many posts? Is there a valid reason for invalid_tag to remain tagged, or some kind of technical limitation with the site? Why not automatically remove from posts? Currently invalid_tag is on 7.1k posts. Same for *_disambiguation tags. I just don't get why these remain taggable to posts.

To indicate that a tag that was added was invalid as an attempt to inform the person tagging to fix it. Same with disambiguation.

deadoon said:
To indicate that a tag that was added was invalid as an attempt to inform the person tagging to fix it. Same with disambiguation.

invalid_tag probably could get auto-removed by a bot every so often, though. unlike disambigs and other stuff in the invalid category it fails to provide useful information for anyone.

sipothac said:
invalid_tag probably could get auto-removed by a bot every so often, though. unlike disambigs and other stuff in the invalid category it fails to provide useful information for anyone.

One could argue that it's presence indicates that you should check the other tags more carefully, after all they've tagged it and left it there.

Annoying bit is when it doesn't tell you which tag was forbidden. So now you have to wonder which tag you messed up on.

hjfduitloxtrds said:
Why is invalid_tag tagged on so many posts? Is there a valid reason for invalid_tag to remain tagged, or some kind of technical limitation with the site? Why not automatically remove from posts? Currently invalid_tag is on 7.1k posts. Same for *_disambiguation tags. I just don't get why these remain taggable to posts.

E621 doesn't have deprecated tags or any of that mess, there simply isn't a way to make them not taggable.