ServicePlans/Telephony/SharedCap
From Emersion
--Shared Cap -Please note Share Cap only supports $ based Caps.
When Shared Cap is enabled, the system will locate other service subscriptions which have periods which end on the same day, and also have Shared Cap enabled and any remaining excess quota that remains can be used to absorb the cost of any other services which have gone into excess.
If you wish to maintain multiple pools of plans which are grouped together, simply use the 'Group Key' as a way to do this. The system will only group subscriptions together if they share a Group Key.