Here is one of the way to create own custom html tag in HTML
STEP 1
Normalize its attributes in your CSS Stylesheet (think css reset) – Example:
stack{display:block;margin:0;padding:0;border:0; ... }
STEP 2
Make it work in old versions of Internet Explorer by appending this script to the head (Important!):
<!--[if lt IE 9]>
<script> document.createElement("stack"); </script>
<![endif]-->
STEP 2
Then you can use your custom tag freely.
<stack> Overflow </stack>
Feel free to set attributes as well…
<stack id="st2" class="nice"> hello </stack>