Case Sensitivity of Property Names, EntitySets, Singletons and Operations

In 4.01 we add support for case-insensitive system query options, operators, built-in functions and keywords.

We don't explicitly say whether property, entity set, singleton, or operation names are case-sensitive or case-insensitive
1) In URLs
2) In payloads

For response payloads, we should mandate that properties are written out in the case they are advertised.

In request payloads, should services support matching property names that differ by case (first looking for a case-sensitive match and, failing that, case insensitive?) or treat as dynamic?

What about in URLs? if resolution fails to find an exact match, should it look for a(n unambiguous) case-insensitive match, or treat as a dynamic property?

What about instance annotations and thus namespaces and aliases?