title: What exactly does TelephonyManager.getNetworkCountryIso() return?
body: <p>I want to find out which country the user is currently in, in the event that a data connection is not available (so <code>Geocoder</code> doesn't work). I think I can do this on phones (not tablets) by using <code>TelephonyManager.getNetworkCountryIso</code>, but I find the documentation is not quite clear enough for me. The <a href="http://developer.android.com/reference/android/telephony/TelephonyManager.html#getNetworkCountryIso()" rel="noreferrer">documentation</a> says:</p>
  
  <blockquote>
    <p>Returns the ISO country code equivalent of the <strong>current registered
    operator</strong>'s MCC (Mobile Country Code).</p>
    
    <p>Availability: Only when user is registered to a network. Result may be
    unreliable on CDMA networks (use getPhoneType() to determine if on a
    CDMA network).</p>
  </blockquote>
  
  <p>What is the precise meaning of <strong>current registered operator</strong> here? Does this simply mean the network which the user is currently connected to, wherever in the world they may be, independent of where their SIM is registered (the "home" network)?</p>
  
  <p>And in what sense is the result <strong>unreliable on CDMA networks</strong>? Does this mean it may return <code>null</code>, or give a non-<code>null</code> but misleading or inaccurate result?</p>