xmlgrrl/UMA-Specifications — Issue #46: Extension mechanism for JSON properties
Author: xmlgrrl
Created: 2012-02-09 21:14:29+00:00
State: open

As discussed in email (http://groups.google.com/group/kantara-initiative-uma-wg/browse_frm/thread/e59373ead388f909):

1) Sections 2.4.1 and 2.4.2 each have a line that says
"... descriptions MAY contain extension properties that are not defined in this specification. The names of extension properties MUST consist of a fully qualified URL or begin with "x-" or "X-"."
What is the purpose of the "x-" or "X-" prefix? My understanding is that this is sometimes used to avoid collisions, although it really just pushes the collision problem into the x-space. The OAuth2 spec has taken the approach of using short names for all parameters described in the document, and requiring extension parameters to either be registered in a central registry or be fully-qualified URI's.

See the rest of the thread for further discussion.

In UMA telecon 2012-02-09, we discussed and resolved this issue:

Paul finds is unable defend the "x-" notation in retrospect. There's a usability problem with URIs. Reverse domain names a la Java are another option people seem to like. And St. Peter made an explicit proposal on this: draft-saintandre-json-namespaces-00 (http://tools.ietf.org/html/draft-saintandre-json-namespaces-00). Can we just say that extension names that are unprotected from collisions are not our problem? Yes.