title: Allow "-" and "." in preg_replace
body: <pre><code>$username = preg_replace("/[^\p{L}|\p{N}]/u", "", html_entity_decode($username));
  </code></pre>
  
  <p>This allows "letters" and "numbers" in the <code>$username</code>, removing everything else.</p>
  
  <p>But how can I also <strong>allow</strong> <code>"."</code> dot symbols in the mix? also <code>"-"</code> would be nice.</p>
  
  <p>Thank you very much!</p>