title: Domain names with dots at the end
body: <p>What is the difference between:</p>
  
  <pre><code>domainname
  </code></pre>
  
  <p>and</p>
  
  <pre><code>domainname.
  </code></pre>
  
  <p>?</p>
  
  <p>For instance, let's suppose <code>msn.com</code> and <code>msn.com.</code>. I tried both here:</p>
  
  <p><a href="http://http-headers.online-domain-tools.com/link/d83cbgIenbU0KGj3/" rel="noreferrer">http://http-headers.online-domain-tools.com/link/d83cbgIenbU0KGj3/</a></p>
  
  <p><a href="http://http-headers.online-domain-tools.com/link/d83d3g2kZ1ioLns4/" rel="noreferrer">http://http-headers.online-domain-tools.com/link/d83d3g2kZ1ioLns4/</a></p>
  
  <p>From the example above we can see that both domain names are valid. However, they are obviously not the same because the responses are different.</p>
  
  <p>I believe that <a href="http://www.ietf.org/rfc/rfc1035.txt" rel="noreferrer">RFC 1035</a> (p. 7) defines domain names. Yet, the grammar does not allow dot at the end of a domain name.</p>