At 14:49 04/07/12 -0700, Tim Bray wrote:3. When Atom software encounters Atom-namespace markup from its own or an earlier version, and doesn't recognize that markup, i.e. it's not in the specification for its version, that's an error.
Big question: How does an Atom implementation that is conformant e.g. to version 2.48 decide whether unknown Atom-namespace markup is 'from its own or an earlier version but not in the specification' or 'from a later version than its own'?
Even more to the point, does it make sense to speak about markup 'from its own or an earlier version but not in the specification'? Sounds like a contradiction to me, unless I missed something.