Information technology — Document description and processing languages — Office Open XML File Formats — Part 3: Markup Compatibility and Extensibility

This Part of ISO/IEC 29500 defines a set of conventions for forward compatibility of markup specifications, applicable not only to Office Open XML specifications as described in Parts 1 and 4 of this Standard, but also to other markup specifications. These conventions allow XML documents created by applications of later versions or extensions to be handled by applications of earlier versions.