Web documents have always been addressed with URIs (in common parlance often referred as Uniform Resource Locators, URLs). This is useful because it means we can easily make RDF statements about Web pages, but also dangerous because we can easily mix up Web pages and the things, or resources, described on the page.

So the question is, what URIs should we use in RDF? As an example, to identify the frontpage of the Web site of Example Inc., we may use http://www.example.com/. But what URI identifies the company as an organisation, not a Web site? Do we have to serve any content—HTML pages, RDF files—at those URIs? In this document we will answer these questions according to relevant specifications. We explain how to use URIs for things that are not Web pages, such as people, products, places, ideas and concepts such as ontology classes. We