2.1.1775 Part 4 Section 14.8.2.5, Additional attributes for writeProtection element (Part 1, 17.15.1.93)

a.   The standard specifies additional attributes for the writeProtection element.

Word ignores the additional attributes (algorithmName, hasValue, saltValue, and spinCount) when attributes from "[ISO/IEC-29500-1] §17.15.1.93; writeProtection" are present.