Part 52 — Numbering
- Subpt. A Scope and Authority §§52.1 to 52.5
- Subpt. B Administration §§52.7 to 52.19
- Subpt. C Number Portability §§52.20 to 52.38-52.99
- Subpt. D Toll Free Numbers §§52.101 to 52.111
- Subpt. E Universal Dialing Code for National Suicide Prevention and Mental Health Crisis Hotline System §§52.200 to 52.203