title: Does HTTP hostname case (upper/lower) matter?
body: <p>In other words, does it matter whether I use <a href="http://www.example.com/" rel="nofollow noreferrer">http://www.example.com/</a> or <a href="http://wwW.exAmPLe.COm/" rel="nofollow noreferrer">http://wwW.exAmPLe.COm/</a> ?</p>
  
  <p>I've been running into strange issues with host-names lately: I have an Apache2.2+PHP5.1.4 webserver, accessed by all kinds of browsers. IE6 users in particular (esp. when their UA string is burdened with numerous BHOs, no pattern yet) seem to have problems accessing the site (cookies disappear, JS refuses to load) when entering via <a href="http://www.Example.com/" rel="nofollow noreferrer">http://www.Example.com/</a>, but not <a href="http://www.example.com/" rel="nofollow noreferrer">http://www.example.com/</a></p>
  
  <p>I've checked the <a href="http://www.faqs.org/rfcs/rfc2616.html" rel="nofollow noreferrer">HTTP</a> and <a href="http://www.dns.net/dnsrd/rfc/" rel="nofollow noreferrer">DNS</a> RFCs, my <a href="https://stackoverflow.com/questions/389456/cookie-blocked-not-saved-in-iframe-in-internet-explorer">P3P policies</a>, cookie settings and <a href="http://en.wikipedia.org/wiki/Same_origin_policy" rel="nofollow noreferrer">SOP</a>; yet nowhere I've seen even a mention of domain names being case-sensitive.</p>
  
  <p>(I know path and query string are case sensitive ( <code>?x=foo</code> is different from <code>?x=Foo</code> ) and treat them appropriately; am doing no parsing/processing on domain name in my code)</p>
  
  <p>Am I doing something wrong or is this just some browser+toolbar crap I should work around?</p>