Specification Stages

Specifications go through various stages of development from which you should have different expectations. This document defines the different stages the SLSA project uses and their meaning for readers and contributors.

Every specification page should prominently display a Status section stating which stage the specification is in with a link to its definition.

Working Draft

This is the first stage of development a specification goes through. At this point, not much should be expected of it. The specification may be very incomplete and may change at any time and even be abandoned. It is therefore not suitable for reference or for implementation beyond experimentation.

A specification may be published several times during this stage as work progresses. The status section of the document may provide additional information as to its development status and whether reviews and feedback are welcome.

In Review

At this stage the document is considered to be feature complete and is published as a way to invite final reviews. Editorial changes may still be made but no addition of new features is expected and short of problems being found no significant changes are expected to happen anymore.


At this stage the document is considered stable. No changes that would constitute a significant departure from the existing specification are expected although changes to address ambiguities and edge cases may still occur.


This stage indicates that the specification is no longer maintained. It has been either rendered obsolete by a newer version or abandoned for some reason. The status of the document may provide additional information and point to the new document to use intead if there is one.