Every protocol listed in this document is assigned to a "maturity level" or STATE of standardization: "standard", "draft standard", "proposed standard", "experimental", or "historic".
4.1.1. Standard Protocol
The IESG has established this as an official standard protocol for
the Internet. These protocols are assigned STD numbers (see RFC-
1311). These are separated into two groups: (1) IP protocol and
above, protocols that apply to the whole Internet; and (2)
network-specific protocols, generally specifications of how to do
IP on particular types of networks.
4.1.2. Draft Standard Protocol
The IESG is actively considering this protocol as a possible
Standard Protocol. Substantial and widespread testing and comment
are desired. Comments and test results should be submitted to the
IESG. There is a possibility that changes will be made in a Draft
Standard Protocol before it becomes a Standard Protocol.
4.1.3. Proposed Standard Protocol
These are protocol proposals that may be considered by the IESG
for standardization in the future. Implementation and testing by
several groups is desirable. Revision of the protocol
specification is likely.
4.1.4. Experimental Protocol
A system should not implement an experimental protocol unless it
is participating in the experiment and has coordinated its use of
the protocol with the developer of the protocol.
Typically, experimental protocols are those that are developed as
part of an ongoing research project not related to an operational
service offering. While they may be proposed as a service
protocol at a later stage, and thus become proposed standard,
draft standard, and then standard protocols, the designation of a
protocol as experimental may sometimes be meant to suggest that
the protocol, although perhaps mature, is not intended for
operational use.
4.1.5. Informational Protocol
Protocols developed by other standard organizations, or vendors,
or that are for other reasons outside the purview of the IESG, may
be published as RFCs for the convenience of the Internet community
as informational protocols.
4.1.6. Historic Protocol
These are protocols that are unlikely to ever become standards in
the Internet either because they have been superseded by later
developments or due to lack of interest.