Well-formed XML (in this case XHTML) needs all tags to have a closing tag, but instead of things like <br></br> you can shorten it to <br />. Or <img src="URIgoesHere" />.

(The joke was s'posed to be me pointing out your attention to detail while myself being a massive pedant, but then I decided not to include it, but then you replied and i did include it in my reply... sorry i am not good at jokes)