pomber/index.html

## index.html
<!DOCTYPE html>
<html lang="en">

<body>

  <my-element></my-element>
  <my-element></my-element>

  <script>
    var MyElementProto = Object.create(HTMLElement.prototype);

    MyElementProto.createdCallback = function() {
      this.innerHTML = "<p>My <b>custom element</b> markup!</p>";
    };

    var MyElement = document.registerElement(
      'my-element', { prototype: MyElementProto }
    );
  </script>

</body>

</html>
	<!DOCTYPE html>
	<html lang="en">

	<body>

	<my-element></my-element>
	<my-element></my-element>

	<script>
	var MyElementProto = Object.create(HTMLElement.prototype);

	MyElementProto.createdCallback = function() {
	this.innerHTML = "<p>My <b>custom element</b> markup!</p>";
	};

	var MyElement = document.registerElement(
	'my-element', { prototype: MyElementProto }
	);
	</script>

	</body>

	</html>