- 401 Unauthorized (status code) - Section 3.1
- 407 Proxy Authentication Required (status code) - Section 3.2
- Authorization header field - Section 4.2
- Canonical Root URI - Section 2.2
- Grammar:
- auth-param - Section 2.1
- auth-scheme - Section 2.1
- Authorization - Section 4.2
- challenge - Section 2.1
- credentials - Section 2.1
- Proxy-Authenticate - Section 4.3
- Proxy-Authorization - Section 4.4
- token68 - Section 2.1
- WWW-Authenticate - Section 4.1
- Protection Space - Section 2.2
- Proxy-Authenticate header field - Section 4.3
- Proxy-Authorization header field - Section 4.4
- WWW-Authenticate header field - Section 4.1