The entire document should be wrapped in an <article>, ideally with a <header>. A second <header> with class="SHORTTITLE" can be used to display a vertical title in the top‑right of the page on supporting browsers ; this title must be a link. It is recommended you use <a href="#">, so that it links to the top of the page.
Main document contents should be in <section>s inside of a <div class="BODY">. In browsers which support them, these sections will be given “ sticky ” headings if the window is tall enough. At most five sections are supported, for reasons of space and stylesheet simplicity.
There is a particular way of marking up section headings to get them to turn into links ; see the source of this page for a demonstration.
It is known that the section numbering is sometimes incorrect in Safari ; this presumably has to do with the way Webkit optimizes large pages and fails to update its counters as they are processed.