Click on an index letter to navigate through our glossary terms:

A B C D E F G H I K L M N O P Q R S T U V W Z

ZONE 1
The most immediate local calling area of a phone system. The term is in use mostly in California, (HG) however HigherGround's Report Commander uses the term Zone 1 to refer to local calls in any state.
ZONE 3
An extended local calling area between the most immediate local calling area and local toll calls. Most states do not have a Zone 3. The term is mostly in use in California.
ZUM (ZONE USAGE MEASUREMENT)
Same as ZONE 3 (see also)