Textbroker has noticed that some authors are having issues using HTML in their orders. Our clients periodically request very minimal HTML coding, and the most common type is adding a URL to the text. You may not know this, but our system actually has an easy-to-use button that inputs HTML for you. This is the safest way to use HTML because sometimes word processors, like Microsoft Word, use smart quotes that the Textbroker system doesn't understand.
Alex from Author Services gives a good overview of basic HTML functions to make your content pop!