NEC Univerge SV8100 Features And Specifications Manual page 1200

Issue 1.0
The system prevents hunting to a UCD (Department) group extension if it is:
Busy on a call
In Do Not Disturb
Call Forwarded
Logged Out
Conditions
When a DIL rings to a UCD (Department) groups, the DIL may follow overflow programming
(Program 22-01-04 and Program 22-08-01).
If an extension has Call Forwarding set, the system does not hunt to the forwarded
extension.
Default Setting
Disabled
2 - 1176
UNIVERGE SV8100
Uniform Call Distribution (UCD)