Forum Userid the unique key? Please confirm
 

For my newly established vBulletin forum which is part of an overall owner site, I now have included and tested sucessfully the database manager implementation for site users to change their vBulletin forum username.

Please confirm whether the userid is the unique key all over the publishing suite 4.0.7 including it's forum and it's blog etc. Just for me to know that there isn't any username references in any table (but userid references only) somewhere out in the big outer vBulletin space.