Artist: untaggable artist
This is used when an artist name is otherwise known, but can't be tagged (due to the artist not having an ASCII-friendly name, and no preexisting tag or alias exists for them, for example). For foreign artist names, if the artist name can be translated so as to be taggable, that should be done instead of using this tag. Or if they have a Twitter page, their Twitter handle can be used. If this tag must be used, the artist name should be provided in the post description so other users can attempt to find a suitable alternative name.
If possible, an alias should be requested when an otherwise untaggable artist name gets a taggable alternative, for future users that try to use the original name.