title: What are the requirements for the event name?
body: <p>I've written an app to publish some events via the open graph api to facebook. For most of the events this works fine. But some events facebook denies:</p>
  
  <p>"OAuthException: (#100) Invalid event name specified: event_info-name"</p>
  
  <p>I searched the facebook doc but I couldn't find a detailed description how the link has to look alike. I convert it to utf8 with utf8_encode (PHP). I guess that the string length is limited. If so: How long can the string be? Are there some other restrictions?</p>
  
  <p>Thanks, Michael</p>