""Errata" means a set of changes or proposed changes to a specification that are not Substantive Changes."
""Substantive Change" is a change to a specification that would require a compliant application or implementation to be modified or rewritten in order to remain compliant."
Given this definition I do not understand how the TC considers the following to be non-substantive changes:
Changes labelled 50, 51, 53, 58, 67, 68, 78: These changes do not alter the xsd, but add new constraints to permissible values of properties e.g. change page width from a float to a positive float. Thus documents written to the current OASIS Standard may now be invalid with these changes if they use values outside those defined in the errata.
Change labelled 83: This is a breaking xsd change. Documents written to the current OASIS Standard may now be invalid with this change.
Change labelled 86: The addition of a RELAX-NG representation of the xsd schema is a new feature that was not in the OASIS Standard.