The MSDN RLT feature allows the attendant to make a call by using the same incoming trunk. RLT helps to provide centralized attendant service by allowing the attendants on the attendant system to reroute calls without tying up additional trunk resources.
Release Link Trunks are typically installed between the attendant system and the non-attendant system. The attendant may receive a call from an RLT and setup an unsupervised transfer to a new party by using the same RLT. Once the attendant releases the trunk, the transfer is initiated.