hoffman%pitt@csnet-relay.arpa (Bob Hoffman) (05/21/85)
These numbers are the Universal Service Ordering Code (USOC). I don't know who assigns them, but a reference to them, including all connections, is available in the FCC Rules and Regulations, Part 68 (Telephone Interconnect). Part 68 is a good reference for anyone interested in telephones. I bought my copy at our local Government Printing Office bookstore. The price was around $5. ---Bob Hoffman/N3CVL Pitt Computer Science