Lists such as 'Allowed Groups' on the VSM/Master page may hold multiple instances of unique elements which is a bit strange since unique identifiers should not appear multiple times in the same list. When administrating very long lists, it's likely one may mistakenly repeat unique elements. This type of selection list is found in the following places * VSM/Master Groups Shadowers * Desktop Customizer/Application Groups Groups Users
Note that deleting one repeated element does not delete every corresponding element.
