NekoAria said:
[...]
The most important thing is that "create rename" perfectly matches the situation of the ambiguous artist name you mentioned above, just like what I did earlier:
rename fujita -> fujita_ichi
artist #547770: created yesterday, terrible ambiguous name that isn't even the actual name as used by the artist.
artist #548171: created yesterday, ambiguous name in need of a qualifier
artist #547946: created yesterday, bad qualifier
The ones I pinged you about: existed for almost a year, not ambiguous.
If an artist tag has existed for some time on Danbooru, chances are they are credited under that name outside Danbooru or people have the tag in their bookmarks or blacklist. An alias makes sure people looking for the artist under the old name get redirected to the new one.
If an artist tag was created yesterday there's not really a point in creating an alias, and if the tag is ambiguous then an alias should not be created.
For small recently created tags I find a manual rename to be faster and there's not really a need to have a record of the rename in the forum since the tag isn't likely to be referenced outside Danbooru at that point. For larger or long-existing tags in need of a rename, I think creating a BUR as you suggested is better because it makes sure you don't forget deleted, banned or blacklisted posts and there is a permanent record of the rename in the forum with a reason for the rename (findable from the "discussions" link in the sidebar when searching the tag)