title: Difference between tel and wtai url schemes
body: <p>I am interested in making phone number links to begin phone calls for users browsing a mobile site.</p>
  
  <p>What are the differences between the <strong>tel</strong> and <strong>wtai</strong> url schemes? Are there other schemes?</p>
  
  <p>How should they be used and in what circumstancs?</p>
  
  <p>Do some devices only recognise one scheme or the other, is either scheme deprecated or likely to be?</p>
  
  <p><a href="http://www.rfc-editor.org/rfc/rfc3966.txt" rel="nofollow">The tel URI for Telephone Numbers</a></p>
  
  <p><a href="http://www.w3.org/wiki/UriSchemes/wtai" rel="nofollow">The WAPI WTAI spec</a></p>
  
  <p><a href="http://developer.apple.com/library/ios/#featuredarticles/iPhoneURLScheme_Reference/Articles/PhoneLinks.html" rel="nofollow">Apple URL Scheme Reference</a></p>