title: Push notification with OneSignal: What means "No Push Token"?
body: <p>I'm using <a href="https://onesignal.com">OneSignal</a> for push notifications.</p>
  
  <p>In the subscribed list some devices/users are marked with <code>No (No Push Token)</code>. Explanation says: <code>This user has no push token and cannot be targeted.</code></p>
  
  <p>That occurs for <code>iOS devices</code> as well as for <code>Android devices</code>.</p>
  
  <p>What does it mean? Why does it happen? How to change it?</p>