title: When is the Scan Credit Card option available on iOS8 Safari?
body: <p>So Safari offers <em>Scan Credit Card</em> feature on iOS8 with some credit card forms.</p>
  
  <p><strong>My question is, how does Safari determine when to offer this option?</strong></p>
  
  <p>So far I found that this option is available on Amazon and PayPal, but none of my credit card input forms were able to reproduce this behaviour.</p>
  
  <p><img src="https://i.stack.imgur.com/mjc7b.jpg" alt="Scan credit card option activation on a form"></p>