An ordered collection of changes that, when applied, will transform a service instance from one consistent state to another. A ChangeSet is viewed as an atomic unit of change - either all of the Changeable elements in a change set will be applied or none of them will be applied. It is anticipated that service implementations will provide a mechanism by which it can apply local business rules to the validation and application of change sets. These rules may include the option to selectively apply, reject, modify or ignore the elements of change sets as they arrive. In this case, it is up to the developers of the business rules to determine what constitutes a "complete" change set that can be applied. PSM An ordered collection of changes that, when applied, will transform a service instance from one consistent state to another. A ChangeSet is viewed as an atomic unit of change - either all of the Changeable elements in a change set will be applied or none of them will be applied. It is anticipated that service implementations will provide a mechanism by which it can apply local business rules to the validation and application of change sets. These rules may include the option to selectively apply, reject, modify or ignore the elements of change sets as they arrive. In this case, it is up to the developers of the business rules to determine what constitutes a "complete" change set that can be applied. PSM A change set whose contents is available as a set of directory entries that allows iteration. A changeable element that occurs in an IterableChangeSet