The link to the Data Providers pack on http://www.nbn.org.uk/Guidebooks/Data/How-to-start-sharing-data-through-the-NBN/The-NBN-Exchange-format.aspx#4 doesn't work (although this one, posted on the forum: http://www.searchnbn.net/library/guide_to_the_NBN/providerPack.jsp does)