The optional UserWriteMask Attributeexposes the possibilities of a client to write the Attributesof the Nodetaking user access rights into account. It uses the AttributeWriteMask DataTypewhich is defined in 0.

The UserWriteMask Attributecan only further restrict the WriteMask Attribute, when it is set to not writable in the general case that applies for every user.

Clientscannot assume an Attributecan be written based on the UserWriteMask Attribute.It is possible that the Servermay return an access denied error due to some server specific change which was not reflected in the state of this Attributeat the time the Clientaccessed it.