XML Schema Versioning Use Cases

This document describes use cases where XML Schemas are being versioned. These are situations when there are more than one XML Schema, and those schemas are related to each other in some way. The use cases describe the desired behaviour from XML Schema processors when they encounter the different versions of schemas and the instances defined by them. This document has been produced by the W3C XML Schema Working Group, to serve as input to the Working Group's work on the versioning of XML Schemas. It is used to define what types of versioning situations that XML Schema should addressing. The use cases illustrate the types of versioning problems that should be solved by versioning mechanisms that might be added to XML Schema. XML Schema might not be able to solve all the use cases, but it is hoped that it can solve a majority of them.