Master Street Address Guide - A listing of all streets and number ranges within a 9-1-1 service area. The streets and address ranges are assigned routing codes, or emergency service numbers (ESN), to enable proper routing of 9-1-1 calls.

MASTER STREET ADDRESS GUIDE. The computerized geographical file which consists of all streets and address ranges within the 9-1-1 system area. This data base is the key to the selective routing capability of Enhanced 9-1-1 systems, and requires constant updating after the initial file is established.

See " Master Street Address Guide."