Set up my own XML namespace?

Question

How can I setup my own XML namespace?

Answer 1

Like this:

To be serious: namespaces should be unique within a world, that's why they typically form the URI. But this is not a necessity. It is great if you own a domain and use it as a namespace, but you don't have. Of course you will run into trouble if someone else uses the same namespaces that is not unique. Using owned domain names guarantees that it will never happen.