Internet Assigned Numbers Authority Hypertext Transfer Protocol (HTTP) Upgrade Token Registry Last Updated 2023-10-20 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registry included below • HTTP Upgrade Tokens HTTP Upgrade Tokens Registration Procedure(s) First Come First Served Reference [RFC9110, Section 16.7] Note Please see [RFC9110], Section 16.7 for details regarding token registrations. Available Formats [IMG] CSV Value Description Expected Version Tokens Reference HTTP Hypertext Transfer Protocol any DIGIT.DIGIT (e.g., "2.0") [RFC9110, Section 2.5] TLS Transport Layer Security ANY DIGIT.DIGIT (e.g., "1.2") [RFC2817] WebSocket The Web Socket Protocol [RFC6455] websocket The Web Socket Protocol [RFC6455][RFC8441] h2c Hypertext Transfer Protocol version 2 (HTTP/2) (OBSOLETE) [RFC9113, Section 3.1] connect-udp Proxying of UDP Payloads [RFC9298] connect-ip Proxying of IP Payloads [RFC9484] Licensing Terms