title: Can CloudKit user phone numbers be retrieved using `CKDiscoverAllUserIdentitiesOperation`?
body: <h2>Background</h2>
  
  <p>I am retrieving all the users for my app using the recommended CloudKit operation, <code>CKDiscoverAllUserIdentitiesOperation</code>.</p>
  
  <p>This operation is designed to returns each user's info in a <code>CKUserIdentity</code> object. The <code>lookupInfo</code> attribute of the user identity has fields that can contain the user's email address and the user's phone number.</p>
  
  <p>e.g.</p>
  
  <pre><code>user.lookupInfo.phoneNumber
  user.lookupInfo.emailAddress
  </code></pre>
  
  <h2>Question</h2>
  
  <p>When I run this operation, I only ever get each user's email address. The <code>phoneNumber</code> field is never populated.</p>
  
  <p>How do I retrieve these user identities and have them include the user's phone number? (Is this possible?)</p>
  
  <h3>Additional Info</h3>
  
  <p>I am able to retrieve individual users with their phone numbers using the <code>discoverUserIdentity(withPhoneNumber...</code> CloudKit function, so I know that these accounts are linked to phone numbers.</p>