Extending RSS 2.0 With Namespaces

Extending RSS 2.0 With Namespaces
This is a very nice description of what a namespace is and why they are necessary. The idea of a namespace is that it allows you to extend the vocabulary of an XML file. So, for example, if you are not satisfied with the choices an RSS feed or a learning object metadata (LOM) gives you, add some of your own. More...