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These were used in the days of MF (Multi-Frequency) signaling. The following is a list of routing codes once used by AT&T and Bell Operating Companies (BOC) that telephone operators used to use to access certain functions on the Bell System network. Old AT&T/Bell System Operator Routing CodesĪt one time many functions that were used by AT&T/Bell System operators were accessed by dialing special codes in the toll system network.
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These are listed here for historical purposes only. These were used by Bell System/AT&T operators for various functions within the network. The following is a list of old Bell System (AT&T Long Lines) routing codes.