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5.2. Informal URN Namespaces

Informal URN namespaces are designed to support experimental or private uses that require rapid registration with minimal review. The NID for an informal URN namespace starts with "urn-" followed by a numeric sequence (e.g., "urn-1", "urn-2", etc.).

Informal URN namespaces are appropriate for:

  1. Experimental use: Temporary identifiers for testing new concepts or technologies
  2. Private networks: Identifiers used only within closed networks or organizations
  3. Rapid deployment: Scenarios requiring immediate use without formal review

The registration process for informal URN namespaces is much simpler than for formal namespaces, requiring no detailed specification documents or community review. However, this simplification also means informal namespaces do not provide the same level of persistence, uniqueness guarantees, or Internet-wide recognition as formal namespaces.

When using informal URN namespaces, note that:

  • They may not be suitable for resource identification requiring long-term persistence
  • Their scope of use may be limited
  • They may not receive widespread recognition or support globally

For applications requiring Internet-wide persistent identification and broad interoperability, registering a formal URN namespace should be prioritized.

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