Errata exists for this version of the document.

Subtypes inherit the parent type’s Attribute values, except for the NodeId. Inherited Attribute values may be overridden by the subtype, the BrowseName and DisplayName values should be overridden. Special rules apply for some Attributes of VariableTypes as defined in 6.2.7. Optional Attributes, not provided by the parent type, may be added to the subtype.