Some HTML tags can also be used in Markdown.
<b>bold</b> bold<i>italic</i> italic<a href="http://stackoverflow.com/">link</a> link<kbd>Ctrl</kbd> CtrlNamed anchors can also be used to allow easier navigation within the document. Note that Stack Overflow Markdown doesn't seem to support this.
<a name="heading"></a>
# Heading 1
Text under the heading
Click on a link like [Go to Heading 1](#heading1) to go to that named anchor.
Text under the heading Click on a link like Go to Heading 1 to go to that named anchor.