title: Keep or discard "www" when saving URLs?
body: <p>I'm creating an application in PHP5 that needs to store a unique URL for a website. For example, if a user enters "<strong><a href="http://www.google.com/" rel="nofollow noreferrer">http://www.google.com/</a></strong>" I'll store it in the DB as "<strong>google.com</strong>" after parsing it. Basically I need a consistent convention for URLs so that there aren't multiple entries for the same site. </p>
  
  <p>Basically, is it OK to be taking the "www" off of all URLs entered? Or should I keep it? </p>