My daily fact learned today is that URLs are not necessarily case-insensitive by definition… I had always assumed they were. Parts of URLs/URIs are case insensitive (domain names, escaped hex characters, and the like), but everything else is up to the implementing server.
I find it very surprising I never noticed this behavior.
But, it seems uber-silly (in a design sense) to have URLs be case sensitive, at least in the WWW case. I suppose it does allow flexibility in design, and in most cases people do not type long URLs.
Anyways, maybe everyone knows this and I am just stupid.