title: How to create a coupon on specific product in Magento?
body: <p>Let's say I have 10% off coupon code.<br>
  This coupon is applicable only to Product B</p>
  
  <p>A customer have in its cart : </p>
  
  <ul>
  <li>Product P1 </li>
  <li><strong>Product B</strong></li>
  <li>Product P2</li>
  </ul>
  
  <p>I don't want my 10% off coupon apply to other product but only to Product B.</p>
  
  <p>Do you know how I can do that within Magento?</p>