ok, let me rephrase the question.

i have a friend who is not using any of the URL comparison methods to compare URL's. his implementation requires that the URL be broken up into path components to be compared.

so,
"http://www.cmu.edu/blah/page"
becomes
"http:", "www.cmu.edu", "blah", "page").

why my friend is wondering is, when comparing URL's that have been divided up like that, what parts should be case-sensitive and what parts shouldn't?