[icebraining]

I disagree. A resource is a concept, not a representation of it. A resource in a car dealership is a 'car', not an ' XML document about a car'. One of the examples given by Fielding are "today's weather in LA"; that's not the representation, it's the actual concept.

The concept of internal data structure doesn't enter the picture at all; for all the client knows, the response might even be generated by a monkey typing on a keyboard.

So if you're using different URLs, you're saying that those are different resources, not multiple representations of the same resource.

Sure, it may be useful and 'practicality beats purity', but it's bending the concept.