Some things we've learned about commenting...
First off, the text-editor when you are replying to a post is rudimentary. HTML tags get stripped before posting.
Good place for composing your initial response.
Then, once you post the comment, go back and edit it. (the edit button is at the end of your subject line, date, time, name, on the main boards.)
The editor that opens is more powerful. Use the tabs for common tags and don't forget to close them. Links are entered into a pop-up window, so you might need to permit that option.
Use a paragraph tag "p" and "/p" in <> 's to force a subject line cut-off.