Support for Versioning and Extensibility

Producers might generate relationship markup that uses the versioning and extensibility mechanisms defined in Part 5: “Markup Compatibility and Extensibility” to incorporate elements and attributes drawn from other XML namespaces. [O1.7]

Consumers shall process relationship markup in a manner that conforms to Part 5: “Markup Compatibility and Extensibility”. Producers editing relationships based on this version of the relationship markup specification shall not preserve any ignored content, regardless of the presence of any preservation attributes as defined in Part 5: “Markup Compatibility and Extensibility”. [M1.31]