HTML code is disabled on almost every forum out there today, including this one, for security reasons, so no HTML code will work.  You have to use BB code.  It has been created specifically for forums and online discussions, plus BB code is easier to learn compared to HTML.  I only need to know a couple BB code tags, but on a quick search, http://www.bbcode.org/reference.php seems to be a good reference for you to learn BB code from if you are interested in using it in the near future.  If not all, most of it should work on this, and just about every other forum out there.  I hope this helps.