Note: Many of these questions are now answered in much more depth in my book, Weaving the Web Frequently asked questions I feel that after a while if I answer the same questions again, I will start answering rather mechanically, and will forget important steps, and after a while it won't make sense. So I have put a few answers from my outgoing mail in this list to save everyone time. But this list is (c) TBL so don't quote directly in the press without permission. Do feel free to quote for school projects. If you are doing a school project, I have a special page of questions that people tend to ask for reports . Thanks. Q: I'm updating my address book entries on (some site which shares contact information). Could you log on and update your address book, please?  Then we can keep in touch and easily track changes to each other's addresses. A: No, I have a FOAF file. Do you?  Why should I have to get an account at every site which keeps a record of me?  That's not using the web. In fact I have that information on the web as data. A URI for me is ttp://www.w3.org/People/Berners-Lee/car\\... That is available in RDF, the W3C standard for generic data interchange, as card.rdf, and also on Notation3 at card.n3.  You can use programs like the tabulator or Foafnaut for reading FOAF files, and various sites index then in various ways. You will notice that my FOAF