[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: Draft wording for resolution of subchannel MPC discussion, April 22 action item done.
ebXML MPC identifiers can be used to implement a wide variety of channel filtering regimes. MPCs are URIs. Because certain URI schemes support "hierarchy" by using the "/" character to separate path segments (such as the "HTTP" scheme), paths may be used to group related channels into channels and subchannels. Although each URI remains a distinct MPC, local conventions may use channels and subchannels to simulate channel filtering of either hierarchical topics (where subchannels are topic specializations) or to simulate fixed, content-based filters. [Query parameters, if supplied, have semantics defined by implementations, and not by this specification. The semantics of paths in simulating topics or content-based filters is not defined by this specification, but would need to be defined by implementations or bilateral participant agreements. -- optional] [I think I mentioned on the call that either HTTP URLs or URNs could be used to simulate MPC subchannels. But I glanced back at http://www.ietf.org/rfc/rfc3986.txt (Uniform Resource Identifier (URI): Generic Syntax ) and realized that "/" is normally given the role of indicating hierarchy in a path. And though URNs look like a structured identifier with hierarchy, I cannot find anywhere that indicates that the ":" in a URN actually indicate path segments. The following are two example URIs and their component parts: foo://example.com:8042/over/there?name=ferret#nose \_/ \______________/\_________/ \_________/ \__/ | | | | | scheme authority path query fragment | _____________________|__ / \ / \ urn:example:animal:ferret:nose And, A path consists of a sequence of path segments separated by a slash ("/") character. A path is always defined for a URI, though the defined path may be empty (zero length). Use of the slash character to indicate hierarchy is only required when a URI will be used as the context for relative references. I am assuming that URNs can in principle,then, have paths that use a ":" to indicate hierarchy because URNs will not be used as a context for relative references. But the semantics of the path following the urn:nid:xxxxx.yyyy.zzzz is up to the namespace registrar, it seems. Anyway you can consult http://tools.ietf.org/rfc/rfc3406.txt on URN best practices to follow the story. It therefore seems to me that we should just omit discussing URNs for MPC identification because it just gets to have a lot of complexity and administrative overhead (useful idea dies by overly intricate specification...) So I omitted URNs from discussion in the draft above.]