Siemens 600 Series User Manual
Page 187
 
Glossary
G–3
HRO (Headset/Recorder Option). A modular upgrade option to 
ROLMphone 600 series telephones. It allows a headset to be attached to the 
telephone.
hunt group. A group made up of telephones arranged to share the call load; 
each group is assigned a dummy extension number called a pilot number.
J
jack. A receptacle used to connect a cord, a plug, an earphone, or a speaker.
K
KEO (Keyboard Expansion Option). A modular upgrade option to 
ROLMphone 600 series telephones. It is designed to provide an additional 
20 lines.
key pad. A group of keys on the telephone used for dialing telephone 
numbers and accessing features. These keys are labeled 0 through 9, 
*, and #.
L
line key. A key on your ROLMphone telephone that provides access to an 
extension. Each line key allows a single telephone call, and a telephone 
with multiple line keys allows a user to place multiple simultaneous calls. 
A user can talk on only one line at a time, though he or she may have 
another call waiting on hold on another line, for example.
M
mute. A feature key that turns the telephone microphone off and on. This 
feature controls the microphones in both the handset and the speakerphone.
O
off-hook. The condition indicating the active state of a data or voice line. 
When you pick up the handset to make or answer a call, the handset is 
“off-hook.”
outgoing call. Any call directed outside of your company’s telephone 
system.