Retire client/device in Mobile Management
In SMP there is the option available to retire a client, so that the client data stays in the database but the license claimed by this device got released.
Symantec Mobile Management does not have such an option. To release a device license the device needed to be delete from the database. There are reasons why a device should stay in the database even if it got no longer managed by Mobile Management.
So an option should be available to retire a device manually or to let a device retiring if not connecting to a server for a specific time.