If you are interested in structured data you should also look at some of the search monkey stuff. Search monkey gives a real insight into how the Y! search engi

If you are interested in structured data you should also look at some of the search monkey stuff. Search monkey gives a real insight into how the Y! search engine uses structured data. http://developer.yahoo.com/searchmonkey/smguide/datarss.html http://developer.yahoo.com/searchmonkey/smguide/datarss.html Essentially the crawler will discover Microformats or RDFa on a site to use in the index. The current suggested vocabularies are Dublin Core, FOAF, VCard, VCal, Review, SIOC, Good Relations, DBPedia and Freebase (http://developer.yahoo.com/searchmonkey/smguide/profile_vocab.html#profile-overview http://developer.yahoo.com/searchmonkey/smguide/profile_voca...). Searchmonkeys use these to visually enhance listing but I'm sure there will be other structured data use in the future, and that the technologies used in BOSS vertical search are in the same family as those used in Searchmonkey.