If one is passing a dataset through HTTP (say, from a WinForm to a Web Service, or vice-versa), I believe what is actually being passed behind the scenes is XML.

Is this also true even when HTTP isn't directly involved? (Say for instance, one middle-tier component function calls another middle-tier component function, and passes a dataset as a parameter...is this also XML?)

We're using datasets almost exlusively to pass parameters (since so many of our parameters are variable length and contain lists of keys, etc.), so I was just curious.

Thanks,
Kevin