Summary

  • RFC 5165 registered ogc as a global URN namespace and placed assignment under the OGC Naming Authority; it did not promise that URNs would remain the preferred form for every future OGC identifier.
  • OGC later made HTTP URIs the default for new persistent public identifiers while retaining equivalent URN forms, normative registers and lifecycle states. Persistence therefore depends on governed continuity, not frozen syntax.

An identifier can persist even after its issuer stops choosing that form for new work. This is the useful tension inside RFC 5165.

Published in 2008 as an Informational RFC, the document registered the Namespace Identifier ogc. A name could take the form urn:ogc:{OGCresource}:{ResourceSpecificString}. The OGC Naming Authority, or ONA, would manage resource classes and their registrations. Other standards bodies could cite OGC schemas, catalogue service types and coordinate reference systems without binding the name to one server address.

The design created a global coordination point, not an eternal product roadmap. OGC’s later Policy Directive 33 instructed the naming authority to issue all new identifiers for persistent public resources as HTTP URIs instead of URNs. New standards and new major versions were to use HTTP forms unless OGC-NA approved an exception.

The easy but wrong reading is that the HTTP decision invalidated urn:ogc. The current OGC Naming Authority policy says something subtler. It defines both HTTP URI and URN schemes for persistent names. The two forms can be equivalent. HTTP identifiers may be resolved through ordinary web infrastructure; URNs do not imply a location or one resolution mechanism.

The namespace survived because the policy could move on.

Registration was an authority map, not a resolver guarantee

RFC 5165 gave ONA responsibility for OGCresource classes and values. It could preserve uniqueness itself or delegate responsibility for well-defined sub-trees. The same document allowed unregistered experimental type values and admitted that separate users could choose the same value for different purposes.

That exception is an unusually clear warning. A string can fit the grammar and still lack production authority. Experimental freedom was safe only because its collision risk was declared and bounded. Promoting such a value into procurement, configuration or archival metadata without checking the register would convert a laboratory convenience into an institutional ambiguity.

The RFC also specified no independent validation mechanism. Assignment rested on ONA procedures. It said the namespace was not listed with a Resolution Discovery System and called that irrelevant. It reported an operational resolver in 2008, but a dated report of operation is not a perpetual availability undertaking.

The current IANA registry still lists ogc and cites RFC 5165. That proves continuity of the NID registration. It does not prove that a particular suffix was issued, remains recommended, maps to a current representation or resolves on the path used by a particular client.

The register became the durable control surface

The 2021 OGC Naming Authority Procedures make the governance mechanics more explicit. Visible name structure is primarily a way for OGC to govern names and preserve uniqueness. Clients may be tempted to infer a new name from the pattern, but the OGC-NA registers are the normative source.

That rule prevents structure from impersonating authority. A developer who knows that one CRS appears below /def/crs/EPSG/0/ can construct another plausible path. Plausibility is not registration.

The policy also distinguishes two availability models. A category A name identifies a discrete resource available from a service and is registered as an individual item. A category X name is constructed from a registered rule or algorithm and may not correspond to a discrete accessible resource. Its class and construction rule are registered instead.

An HTTP response is therefore not the universal test of whether an OGC name is legitimate. Some names should retrieve a discrete representation; others are valid because they conform to an authorised construction rule. Conversely, a server can return bytes for an unregistered path. Retrieval and authority are separate receipts.

Persistence needs a history, not an immortal “valid” bit

The present policy records state changes. A submitted item enters before acceptance. An accepted item becomes valid. It can later be superseded, with links to predecessor and successor, or retired when it is no longer recommended and no replacement exists. Experimental and invalid states carry different meanings again.

This is how a persistent system admits change without erasing history. “Superseded” should not make an old dataset unintelligible. “Retired” should not silently redirect every historical reference to a new concept. “Invalid” should not be confused with “old”. A resolver or catalogue must preserve the distinction if downstream systems are expected to reproduce an earlier decision.

The same discipline applies to the URN-to-HTTP policy shift. A new issuance preference does not rewrite old documents. Equivalence data can join the forms, register state can say which form is recommended, and predecessor links can preserve the path by which a user arrived there.

Two successful URLs are only two receipts

During this research, the captured OGC HTTP definition endpoints for EPSG 4326 and 26986 returned HTTP 200 after redirects. That is useful evidence about those requests at that time. It is not a census of every OGC identifier, resolver, representation, cache, client or historic version.

A defensible operational chain records:

  1. the IANA NID registration;
  2. the OGC name class or specific item in the normative register;
  3. the authority or delegated sub-tree that issued it;
  4. its status and predecessor or successor links;
  5. any authoritative equivalence between URN and HTTP forms;
  6. the resolver or HTTP response, timestamp and representation negotiated;
  7. the retrieved content and version; and
  8. the client decision or conformance outcome.

No row can be replaced by the row above it.

Sources