title: Is it possible to have one (single) character top level domain name?
body: <p>I'm writing a Regex to validate email. The only one thing confuse me is:</p>
  
  <p><strong>Is it possible to have single character for top level domain name?</strong> (e.g.: <strong>lockevn.c</strong>)</p>
  
  <p>Background: I knew top level domain name can be from 2 characters to anything (.uk, .us to <a href="http://www.canon.com/news/2010/mar16e.html" rel="noreferrer">.canon</a>, .museum). I read some documents but I can't figure out does it allow 1 character or not.</p>