HTTP/2 200 date: Mon, 14 Jul 2025 13:46:31 GMT content-type: application/xml cache-control: public, max-age=3600 cross-origin-opener-policy: same-origin expires: Mon, 14 Jul 2025 14:46:31 GMT referrer-policy: same-origin vary: Cookie, origin, Accept-Encoding x-content-type-options: nosniff x-frame-options: DENY x-resolution-methods: manual;auto;fallback x-resolution-outcomes: ;RfcAdapter: using docid IETF RFC 6335 -> using query @.type == "IETF" && @.primary == true && @.id == "RFC 6335" -> 1 found,; last-modified: Mon, 14 Jul 2025 13:46:31 GMT cf-cache-status: EXPIRED server: cloudflare cf-ray: 95f1775e9c022ffb-BLR content-encoding: gzip alt-svc: h3=":443"; ma=86400 This document defines the procedures that the Internet Assigned Numbers Authority (IANA) uses when handling assignment and other requests related to the Service Name and Transport Protocol Port Number registry. It also discusses the rationale and principles behind these procedures and how they facilitate the long-term sustainability of the registry. This document updates IANA's procedures by obsoleting the previous UDP and TCP port assignment procedures defined in Sections 8 and 9.1 of the IANA Allocation Guidelines, and it updates the IANA service name and port assignment procedures for UDP-Lite, the Datagram Congestion Control Protocol (DCCP), and the Stream Control Transmission Protocol (SCTP). It also updates the DNS SRV specification to clarify what a service name is and how it is registered. This memo documents an Internet Best Current Practice.