|Characters to prevent during new account creations.|
|Introduced in version:||1.15.0 (r48765)|
|Removed in version:||still in use|
|Default value:||'@:' (since wmf/1.26wmf6)|
|Other settings: Alphabetical | By function|
Characters to prevent during new account creations.
The @ sign is prohibited by default, because MediaWiki uses it internally for users that have their account in another wiki (interwiki users). The : sign is prohibited because the validity of usernames in different wikis differs due to different namespace and interwiki configuration. If you allow the "@" in usernames, you should also set $wgUserrightsInterwikiDelimiter. Otherwise you won't be able to give users with an "@" in the username different permissions using the normal way (though permissions can still be set via user ID). However, you are free to allow the ":" in usernames as long as you don't run multiple wikis with shared database or Extension:CentralAuth, and you don't create new namespace or interwiki prefixes which make existing username invalid.
This is used in a regular expression character class during registration (regex metacharacters like / are escaped).
In case user names containing @, # and € should be prevented, the following setting is used:
$wgInvalidUsernameCharacters = '@#€';