The title attribute will be the content of the caption by default, you can change it by the caption option.

    <div class="demo" id="container">
        <ul>
            <li>
                <a href="#"><img src="img/1.jpg" title="this is a normal caption" /></a>
            </li>
            <li>
                <a href="#" >
                <img src="img/2.jpg" title="<h3 style='color:yellow'>custom the caption</h3><hr/><p>with html, you can put link, button or any other element you want </p>" />
                </a>
            </li>
            ...
        </ul>
    </div>

     $(function() {

         $('#container').sliphover({
             caption: 'data-caption'
         });
     })