title: Validation/Format of display-name in from header
body: <p>I need to know what are the rules for validation/format from(<code>name-addr</code>) field in the email.
  In rfc explained the format of <code>name-addr</code>, but goes into detail about the <code>display-name</code>.</p>
  <p>Like this:</p>
  <pre><code>From: John Q. Public &lt;JQP@bar.com&gt;
  </code></pre>
  <p>I want to know the characters and length allowed.
  How do I know that <code>John Q. Public</code> has valid characters?
  Should I allow only printable US-ASCII characters ?</p>
  <p>I consulted the <a href="https://www.rfc-editor.org/rfc/rfc2822#section-3.4" rel="nofollow noreferrer">RFC 2822</a> and not found on the specific format of a display name</p>