Status Levels for SP RFCs
Authors: Garrett D’Amore
This document defines the meaning of the "Status" keyword used to label RFC documents for the Scalability Protocols suite of protocols.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
In order to ensure compatibility across different implementations of the SP protocols, it is important to document the details of those protocols, including expected mandatory and optional behaviors. These are documented in the form of RFC (Request for Comments) documents, which are posted online for review and reference by implementors.
A document undergoes a lifetime transition. During its early phases, the authors and initial implementors may be uncertain about the details of the protocols, and the document itself may be evolving rather quickly. Conversely, at some point in the near the end of a document’s life time, a protocol may be deprecated, indicating that it should not be used by new implementations, or even retired entirely, where it should not be in use at all.
Understanding the phase a document (and the protocol described) is in is important for potential implementors, in order to avoid certain development risks and set expectations for likely changes.
All RFCs start life as Draft status. These may very from extremely preliminary documents with no existing complete implementation, to documents where several implementations exist, but which have not been sufficiently reviewed by the SP community.
The yellow color in the badge serves as a warning against depending upon the document details too deeply.
A Stable RFC is one that describes a protocol which itself is "finished", and suitable for implementation by other implementors. Additionally, the document itself must have been reviewed for accuracy and completeness.
As a final check, there should be at least two independent implementations of the RFC in order to qualify for Stable status.
The bright green badge color indicates that the document and the protocol are suitable for broad adoption by implementors.
A Deprecated RFC documents a protocol that is no longer recommended for use by implementors. Generally, a newer Stable RFC will document a newer protocol that should be used instead.
However, deprecated protocols are expected to be found in the wild, and implementors MAY choose to implement them anyway for compatibility reasons.
The orange status badge color serves as a warning to implementors that they are discouraged from implementing this, and should look for a newer protocol instead.
A Retired RFC is one that has been removed from service.
Generally these RFCs document protocols that new implementations MUST NOT implement, and that existing implementations SHOULD remove from service at their earliest opportunity.
The main motivation for retiring RFCs will be to cover the case where severe defects in an implementation exist. For example, in the 802.11 arena, WEP would be a protocol that should be Retired, as it is defective in ways that are dangerous to the user.
An RFC may also be retired when the protocol is believed to have become extinct in the wild.
The purpose of keeping the retired RFCs available is for historical context. It may also help some party in the event that they come across an actual implementation in the wild.
The red status color should be a strong indicator that nobody should be using RFCs with this status.