[1] draft-mogul-http-dupsup-00 - Duplicate Suppression in HTTP (2014-10-26 21:59:10 +09:00 版) <http://tools.ietf.org/html/draft-mogul-http-dupsup-00#section-5.2.2>

[2] RFC 4229 - HTTP Header Field Registrations (2014-11-02 18:53:20 +09:00 版) <http://tools.ietf.org/html/rfc4229#section-2.2.10>