https://login.wikimedia.org/wiki/Special:ListGroupRights
Some pretty weird (non-default) user groups and user rights here. Example:
Use the VIPS scaling test interface Special:VipsTest (vipsscaler-test)
For all users? Weird. Account creators user group? Really? Weird.
URL: https://login.wikimedia.org/wiki/Special:ListGroupRights
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=59702