Let's say that we have users from the two different countries: England and Norway. We would like the ability to let the users choose whether he or she would like to use the Norwegian element names or the English element names in the XML document.

To solve this problem, we could define a substitutionGroup in the XML schemas. First, we declare a head element and then we declare the other element which state that they are substitutable for the head element.

In the example above, the "name" element is the head element and the "navn" element is substitutable for the "name".

Look at this fragment of an XML schema as follows:

A valid XML document (according to the schema above) could looks like this:

or like this as follows:

To prevent other element from substituting with a specified element, use the block attribute:

Look at this fragment of an XML schemas:

A valid XML document (according to the schema above) looks like as follows:

But this is valid for more days:

The type of the substitutable element must be the same as, or derived from, the type of the head element. If the type of the substitutable elements is the same as the type of the head element you will not have to specify the type of the substitutable element.

Note that all element in the substitutionGroup (the head element and the substitutable elements) must be declared as global elements, otherwise it will not work!

Global elements are elements that are immediate children of the "schema" elements! Local elements are elements nested within the other elements.