Panasonic DBS-2.3-400 Programming Manual page 91

Section 400-Programming Chapter 1. System Programming (FF1)
Third-Party Voice Mail. This feature can be used with Panasonic's Voice
Mail system or with third-party Voice Mail systems. If the feature is used
with third-party Voice Mail systems, the Voice Mail can be connected
through analog extension ports or OPX ports.
Call Forward ID Code for DID/DNIS Calls To An Extension. If a DID/
DNIS call is assigned to ring an extension, and the extension is programmed
to forward to Voice Mail, only the Call Forward ID Code will be transmitted
to Voice Mail (the DID/DNIS digits will not).
DID/DNIS Data Transmission. The DID/DNIS digits are transmitted over
the API link using the existing API key code packet.
DBS-2.3/9.2-400 DBS Manual - Revised April 2000 Page 1-47