lucy24 - 8:58 pm on Sep 13, 2012 (gmt 0)

as does the upper and lower cases anything after the first trailing slash does not

Right. The domain name is case-insensitive (you can amuse yourself by looking up random domains at DomainTools or similar and see their wild & wonderful best guesses at intended casing :)); the rest of the URL is case-sensitive. Technically it depends on the server, but you should always treat it as case sensitive. Regular Expressions as used in Apache are case sensitive unless you expressly tell them not to be.