An empty XML element is as follows:

The "product" element above has no contents at all. To define a type with no content, we must define a type that allow only elements in its content, but we do not actually declare any elements, like this:

In the example above, we define a complex type with a complex contents. The complexContent element signal that we intend to restrict or extend the content model of a complex type, and the restriction of integer declares one attribute but does not introduce any element content.

However, it is possible to declare the "product" element more compactly,as follows:

Or you can give the complexType elements a name, and let the "product" element have a type attribute that refers to the name of the complexType (if you use this method, several elements can refer to the same complex type):