[1] [CITE@en[draft-ietf-http-options-02 - Specification of HTTP/1.1 OPTIONS messages]] ([TIME[2014-10-17 22:55:52 +09:00]] 版) <https://tools.ietf.org/html/draft-ietf-http-options-02#section-3.4>

[2] [CITE@en[RFC 4229 - HTTP Header Field Registrations]]
( ([TIME[2014-11-02 18:53:20 +09:00]] 版))
<http://tools.ietf.org/html/rfc4229#section-2.2.1>