serializing datamodels

It occurs to me that we probably should say something about how the ECMAScript and XPath datamodels are serialized when using <send> or <invoke>.  So, a couple of questions:

1.        Is it correct to say that atomic ECMAScript types are serialized as strings?  I'm thinking of saying something like:  a) atomic types should be serialized as strings b) complex types should be serialized as JSON if the processor supports it c) the serialization of objects that can't be serialized as JSON (and of all objects in processors that don't support JSON) is platform-specific

2.       Is the serialization of XML so obvious that we don't need to say anything? Or do we say "Values from the XPath datamodel should be serialized as strings"?


-          Jim