xsd: How to extend a type with an unordered list of elements

Question

This is a part of my xml schema

Answer 1

One-and-half year after this question and the accepted answer were posted, XSD 1.1 was published. In this version it is possible to specify what the OP asked for because a number of restriction on xs:all were lifted. One of them is that it is now possible to extend an xs:all.

Using XSD 1.1 you can specify the following:

This defines the following types:

• Person: an abstract type with optional unordered name and phone elements;
• Friend: extends Person adding an optional address element to the list of unordered elements;
• Coworker: extends Coworker adding an optional office element to the list of unordered elements.

Note that this solution does not work for every XML processor: even though 8 years have passed since the publication of XSD 1.1, a lot of processors still only support XSD 1.0.