"The Hypertext Transfer Protocol (HTTP) is a family of stateless, application-level, request/response protocols ... HTTP is a stateless request/response protocol for exchanging 'messages' across a connection." RFC9110.
“RFC 2817 Upgrading to TLS Within HTTP/1.1” (2000年5月). 2019年4月26日閲覧。 “The CONNECT method was originally described in a Work in Progress titled, "Tunneling TCP based protocols through Web proxy servers", by Ari Luotonen of Netscape Communications Corporation.”