title: NDEF message to switch Wi-Fi on/off
body: <p>We're creating a simple android app for reading and writing to <code>NFC</code> tags, focused mostly on the <code>NDEF</code> technology. We're able to write an <code>NDEF</code> message with an <code>NDEF</code> record containing a URI.</p>
  
  <p>However, we also need to write such message that turns the <code>NFC</code> tag into a Wi-Fi switch - reading it would cause Wi-Fi to turn on/off.</p>
  
  <p>What kind of data do we need to write to the <code>NDEF</code> record to achieve this? Is it some sort of binary data, or a special "syatem" URI that android recognizes and takes appropriate action?</p>