Will Atom have a "don't process invalid documents" rule?

[Simon Willison <cs1spw@xxxxxxxxxx>]

Tim just mentioned a mandatory order for the <issued>, <modified> and 
<created> elements, hence my question. Will the final Atom specification 
include text along the lines of "client implementations MUST reject Atom 
feeds if they are invalid". The benefits of this are obvious: if clients 
follow the spec, anyone implementing their own Atom feed will instantly 
realise if they have made a mistake when they go to test it. The instant 
disadvantage is that Aggregators are tools for users: if a feed is 
invalid, user's would rather it "just worked" than it threw an error 
message.

It's an age old debate I know, but has it been discussed with respect to 
Atom?

Cheers,

Simon Willison