extensibility of CoRIM locator-map

[thomas-fossati]

Discuss extensibility of CoRIM locator-map.

Previous discussion captured here:

@nedmsmith: "corim-locator-map isn't extensible today. If an alternative to URL/URI is needed, the spec can be updated. However, due to the popularity of the Internet most every other form of reference has a URI representation."

@thomas-fossati: "I haven't pondered enough about the corim-locator-map to say with sufficient confidence that all we have is all we need. Adding a CDDL socket here may be the right approach, lazy as it sounds..."