Q: I found an old L.A. phone book with listings made up of two letters and five digits, such as MA3-2489. What did the letters refer to?
A: For decades those alphabetical pairings served as area “exchanges” that corresponded to neighborhoods across the country. Locally, “MA” referred to Madison (which was downtown), CR to Crestview (Beverly Hills), and HO to Hollywood. In 1962, when AT&T began expanding its service in L.A., rather than devise more combinations the company began to phase out the lettered prefixes in favor of all-digit listings.