Mitel 6865i User Manual page 112

LINE KEYS AND PROGRAMMABLE KEYS
Programmable Keys
Select from Key 1 through Key 8.
2.
In the Type field, select Discreet Ringing.
3.
Click Save Settings.
4.
Expansion Module Keys
Select from Key 1 through Key 16 (M680i) or Key 84 (M685i).
5.
In the Type field, select Discreet Ringing.
6.
Click Save Settings.
7.
DISCREET RINGING KEY
102