In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force (IETF).
Engineering contributions to the IETF start as an Internet Draft, may be promoted to a Request for Comments, and may eventually become an Internet Standard.
An Internet Standard is characterized by technical maturity and usefulness. The IETF also defines a Proposed Standard as a less mature but stable and well-reviewed specification. A Draft Standard is a third classification that was discontinued in 2011. A Draft Standard was an intermediary step that occurred after a Proposed Standard but prior to an Internet Standard.
As put in RFC 2026:
In general, an Internet Standard is a specification that is stable and well-understood, is technically competent, has multiple, independent, and interoperable implementations with substantial operational experience, enjoys significant public support, and is recognizably useful in some or all parts of the Internet.
Only the IETF, represented by the Internet Engineering Steering Group (IESG), can approve Standards Track RFCs. The definitive list of Internet Standards is maintained in the Official Internet Protocol Standards. Previously, STD 1 used to maintain a snapshot of the list.RFC 7100 Retirement of the "Internet Official Protocol Standards" Summary Document
If an RFC is part of a proposal that is on the Standards Track, then at the first stage, the standard is proposed and subsequently organizations decide whether to implement this Proposed Standard. After the criteria in RFC 6410 is met (two separate implementations, widespread use, no errata etc.), the RFC can advance to Internet Standard.
The Internet Standards Process is defined in several "Best Current Practice" documents, notably BCP 9 ( RFC 2026 and RFC 6410). There were previously three standard maturity levels: Proposed Standard, Draft Standard and Internet Standard. RFC 6410 reduced this to two maturity levels.
A Proposed Standard specification is stable, has resolved known design choices, has received significant community review, and appears to enjoy enough community interest to be considered valuable. Usually, neither implementation nor operational experience is required for the designation of a specification as a Proposed Standard.
Proposed Standards are of such quality that implementations can be deployed in the Internet. However, as with all technical specifications, Proposed Standards may be revised if problems are found or better solutions are identified, when experiences with deploying implementations of such technologies at scale is gathered.
Many Proposed Standards are actually deployed on the Internet and used extensively, as stable protocols. Actual practice has been that full progression through the sequence of standards levels is typically quite rare, and most popular IETF protocols remain at Proposed Standard.
An Internet Standard ensures that hardware and software produced by different vendors can work together. Having a standard makes it much easier to develop software and hardware that link different networks because software and hardware can be developed one layer at a time. Normally, the standards used in data communication are called protocols.
All Internet Standards are given a number in the STD series. The series was summarized in its first document, STD 1 (RFC 5000), until 2013, but this practice was retired in RFC 7100. The definitive list of Internet Standards is now maintained by the RFC Editor.
Documents submitted to the IETF editor and accepted as an RFC are not revised; if the document has to be changed, it is submitted again and assigned a new RFC number. When an RFC becomes an Internet Standard (STD), it is assigned an STD number but retains its RFC number. When an Internet Standard is updated, its number is unchanged but refers to a different RFC or set of RFCs. For example, in 2007 RFC 3700 was an Internet Standard (STD 1) and in May 2008 it was replaced with RFC 5000. RFC 3700 received Historic status, and RFC 5000 became STD 1.
The list of Internet standards in RFC 5000 ends with STD 68 (RFC 5234, ABNF) published in 2008. It does not cover STD 69 (a set of five EPP RFCs), STD 70 (RFC 5652, CMS) published in 2009, STD 71 (RFC 6152, 8BITMIME), and STD 72 (RFC 6409, Mail Submission) published in 2011.