kbd>Tab</kbd> character is indentation; conversely, using the <kbd>Space</kbd> character for
  indentation carries no semantic meaning&mdash;if you code this way your indentation schema may as well be a form of
  <abbr title="American Standard Code for Information Interchange">ASCII</abbr> art. ;-)</p>

<h3>Heading level 3</h3>
<p>The
  <del>slow</del>
  quick brown fox jumped over the lazy dog. The
  <ins>ins (insert)</ins>
  element, unlike the dog cannot jump over anything, so it cannot span cross paragr