How to close HTML tags

On blogger one gets the option to use bold italics and underlining when we make comments
Most people end up seeing this error Your HTML cannot be accepted: Tag is not closed: <_b_> .Comment formatting is a very simple but unexplained feature of blogger.

To close a HTML tag <> BOLD <> ITALICS <> UNDERLINE
1) Type the tag
<_b_> (or 'i' or 'u')
2) Type your text
<_b_>This text will be bold
3) Close your tag
<_b_>This text will be bold but <_/_b_>
4) Voila!
In the end the HTML tags will be gone.

(Always preview your comment first to make sure its correct) The _ are not really supposed to be in there...

You can also enclose tags within tags similar to (multiple (parentheses in an (equation)))