NEC Univerge SV8100 Features And Specifications Manual page 241

UNIVERGE SV8100 Issue 11.0
Operation
To override an extension Call Forwarding or Do Not Disturb:
1. Call the forwarded or DND extension.
2. Press the Override key (Program 15-07 or SC 751: 37).
Call Forwarding/Do Not Disturb Override 2 - 209