Verifies whether a user account with the specified username is already present.
isusernametaken( username )
username: (Text) The username to check against the current list of active and deactivated users.
Returns a value of type Boolean.
false result indicates that the username is available to use when creating a new user, unless the username contains special characters that are not permitted.
Both active and deactivated user accounts are referenced.
The username parameter is case-sensitive, however you will not be able to create a username if case-insensitive matches exist.
You can copy and paste these examples into the Expression Rule Designer to see how this works.