I was interested to know the answer to this myself so I traced the answer to -
admin folder - Dbsql.pm - sub user_validate
which is is being called by - admin folder - Dbsql folder - Admin.pm - sub user_update
This is used when you try adding via your DBMan SQL Admin.
If you allow users to sign-up their own account it does not run the same format check and you can add the user with their email address as the username provided it's less than 12 character (which most probably aren't).
Simon.
admin folder - Dbsql.pm - sub user_validate
which is is being called by - admin folder - Dbsql folder - Admin.pm - sub user_update
This is used when you try adding via your DBMan SQL Admin.
If you allow users to sign-up their own account it does not run the same format check and you can add the user with their email address as the username provided it's less than 12 character (which most probably aren't).
Simon.