There are three different shortcodes to add a separator to your text:
[ hr ]
[hr]
The hr adds a line to break the text in two part (it means in facts “horizontal rule”).
[ totop ]
[totop]
The totop element is very similar to a hr but it displays a link to automatically scroll to the top of the page.
[ clear ]
[clear]
The shortcode above simply adds a div:
<div style="clear: both;"></div>
to your page, very useful when you need to separate floating elements.