You can
bold,
italicize,
underline, indent, and more!
Most formatting is based in HTML so here's a quick chart:
<b>text</b> -->
text.
<em>text</em> -->
text.
<u>text</u> -->
text.
<font color="red">text</font> -->
text.
<a href="www.google.com">text</a> -->
text.
<img src="url_to_img.png"> -->