47 CFR §64.2329

1. (a)A carrier shall provide subscriber list information obtained in its capacity as a provider of telephone exchange service to a requesting directory publisher in the format the publisher specifies, if the carrier's internal systems can accommodate that format.
2. (b)If a carrier's internal systems do not permit the carrier to provide subscriber list information in the format the directory publisher specifies, the carrier shall:
   1. (1)Within thirty days of receiving the publisher's request, inform the directory publisher that the requested format cannot be accommodated and tell the directory publisher which formats can be accommodated; and
   2. (2)Provide the requested subscriber list information in the format the directory publisher chooses from among the available formats.