Model Context Protocol Docs Use Date-Based Versioning, Not Version Numbers

The Model Context Protocol (MCP) documentation is organized across three core resources: a specification, a machine-readable schema, and a changelog, each serving a distinct purpose. Revisions are identified by date rather than version numbers, meaning a valid citation must include the specific date found in the URL path under /specification/. Older revisions remain publicly accessible, so a client negotiated to an earlier revision is unaffected by newer ones unless a server drops support for that older text. The schema is considered more authoritative than prose for precise field definitions, enum values, and error codes. The changelog serves as the definitive record of what changed between revisions and references the underlying proposals that drove each update.