Add or Edit User Group Access - Mediawiki

Add User to Group

If you are a wiki Sysop you can add an account to an access group. Access groups can be setup in advance by a System Administrator.

Make sure the user has logged in at least once
Login to the wiki (you'll need to be a member of the Sysop group)
Go to Special Pages > Userrights and enter the username of the person to be added (Note: if you're not sure you can also go to Special Pages > User List to see a listing of everyone's that has logged into the site.)
From the Available Groups column select the group the user should be added to.
Click the Save User Groups button to apply