Author: ayg
Description:
It's been forbidden to create accounts with at-signs in them for some time, because this conflicts with interwiki syntax and will cause problems for SUL. More immediately, such users cannot be affected by Special:Userrights, which caused some confusion on enwiki earlier with the wider access that's been given. A maintenance script runnable from update.php needs to find and rename all such users (with suitable warning), and @ should be made entirely invalid in usernames instead of just invalid on creation.
Version: 1.12.x
Severity: normal