11.3.2. Service Information 
An internal or external extension A (any device type), who was requesting
a call service from the operator, can be retrieved by the operator, if
the operator has prior transferred the extension A to
- An alerting internal or external extension B and extension B has not answered yet
- An alerting internal or external extension B with activated CFNR feature and the call was forwarded to extension C and extension C has not answered yet
- A hunt/distribution group and no group member has answered yet
- A paging device and the paged user has not answered yet
- An ACD group and no agent or supervisor has answered yet
- An undialed CO trunk line and the remote CO extension has not answered yet
- A busy internal or external extension B (w/o camp-on)
- An alerting or busy internal or external extension B and the operator has provided incoming call service to another extension C but has not transferred extension C to somewhere else
An internal or external extension A (any device type), who was requesting
a call service from the operator, can not be retrieved by the operator,
if the operator has prior transferred the extension A to
- An internal or external extension B in talk state
- An alerting internal or external extension B and extension B has answered the call after the transfer
- An alerting or busy internal or external extension B and the call was already released
- An alerting or busy internal or external extension B and a recall is queued to the operator from extension B due to timer expiration
- An internal or external extension B and extension B has parked the call to another internal or external extension C
- an alerting or busy internal or external extension B and all loop keys on the ACWin (MQ) console are busy
- Voicemail server