Via Danny Ayers' blog [1], Mark Nottingham's proposal to add profiles to HTTP headers seems very relevant to microformats: http://www.ietf.org/internet-drafts/draft-nottingham-http-link- header-00.txt It would allow for HEAD requests to identify pages containing microformats without downloading the full document. Peace, Scott [1] http://dannyayers.com/2006/06/23/return-of-the-http