The optional WriteMask Attributeexposes the possibilities of a client to write the Attributesof the Node. The WriteMask Attributedoes not take any user access rights into account, that is, although an Attributeis writable this may be restricted to a certain user/user group.
If the OPC UA Serverdoes not have the ability to get the WriteMaskinformation for a specific Attributefrom the underlying system, it should state that it is writable. If a write operation is called on the Attribute, the Servershould transfer this request and return the corresponding StatusCodeif such a request is rejected. StatusCodesare defined in OPC 10000-4.