We can find a * in almost all offers. There will be small description for that star, which can be found on the bottom of the document. Here you can find the code for creating that small font.
<small> is the HTML tag which is used for it.
<h1>Todays Deal exciting offers for <i>Mobiles & Power banks</i><sup>*</sup></h1>
<p><small>* Terms and Conditions apply</small></p>