|id||unique id||A unique identifier for this display_rule, e.g. 0, 1, 2, etc.|
|action_id||A valid action as defined in the phone's Contacts file||Sets the action_id for the display rule to act upon|
|phone_state||idle, hold, transfer, incoming/transfer, incoming, connected, dialing, calling, failed||Defines the state of the local phone during which the rule will be acting. If not specified in a rule, all states are matched. Note that this list of states differs from the larger list of states available for BLF key action mappings.|
|target_status||unknown, idle, on_hold, ringing, on_the_phone, on_hold_ringing||Optional. Sets the status of the subscribed to contact that must be matched for this display rule to be in effect|
|show||Boolean||If set to yes, shows a particular action; if set to no, hides the action. To hide an action for all states and only show it for some states, first declare the action to have a false show, then declare it to have a true show for only a particular state or states.|
Digium phones have a Voicemail application that allows the forwarding of voicemails to a Contact. When a user engages the forward function from within the Voicemail application, the user is then presented with a filtered list of contacts to whom forwarding is possible. The filtered list of contacts is defined by the set of contacts that are contained on a server with the same server_uuid as the current phone, and that are of the type 'sip', 'zap', or 'virtual,' and that have an account_id that matches the target voicemail box.