If you've already read my XML tutorial , many will be familiar to you. The head and body tags are now mandatory. Every tag must be closed. If you only had one table on a page, you didn't need the end TD and end TR tags. All tags that require end tags get end tags.
Empty tags get a terminating slash.
An empty tag is a tag that doesn't require an end tag. This does not apply to attributes, only tags. You may have noticed that I have quotes around all of the attributes. Tags may not nest. In HTML, this is an acceptable format.