Ambiguous: xinjinjumin is the default username for Lofter accounts, similar to a default Pixiv stacc (user_*), not an actual name. Create your new artist entry with the proper artist name (see howto:artist or ask in topic #8199 if you need help) and add your posts to that new tag instead.
See xinjinjumin* for a list of artists who are still using the default Lofter username.
This tag is deprecated and can't be added to new posts.
