title: Validating a prename and surname
body: <p>I want to validate a prename and surname for users to register at a worldwide social community.</p>
  
  <p>I want to allow all these language-related special characters like <code>ÄÖÜÀýéè</code> and a <em>maximum of <strong>3</em></strong> prenames, all seperated with a space (if there are more than 1 prename).
  Also no underscores should be allowed or other special chars, but minus (-) should be allowed.</p>
  
  <p>That's all I can think of what should be allowed in a name. I don't know how it is in other countries than Germany, but here you can have up to 3 prenames and a surname can also have 2 words like "von Seidenfeld".
  Maybe you can also give me some more suggestions here, because I want to cover this name-validation-system for <strong>every</strong> full name around the world.</p>
  
  <p>I also know I've to use RegEx, but I don't know how to allow only these conditions that I just wrote. </p>
  
  <p>What I have so far: </p>
  
  <pre><code>if (!preg_match('/^(\pL+\s+)$/u', $value)) echo 'error';
  </code></pre>
  
  <p>or view here: <a href="http://regex101.com/r/tE0uQ5" rel="nofollow">http://regex101.com/r/tE0uQ5</a> (sadly doesn't work, no matches)</p>