FYI: http://www.snellspace.com/wp/?p=193
Abstract: Proposes two new elements that allow entries to be ordered within a feed. Full details in my blog post.
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:o="http://www.snellspace.com/atom/extensions/proposed"> ... <o:indexed /> <entry> ... <o:index>1</o:index> </entry> <entry> ... <o:index>2</o:index> </entry> <entry> ... <o:index>3</o:index> </entry> </feed> - James