SDMN11 — ItemDefinition class naming and semantics

SDMN ItemDefinition would seem to be a major extension of the DMN ItemDefinition class. It is documented as: "The itemDefinition element is the mechanism for providing the data structure of DataItems. It is contained within a SDMNDefinitions"

Since SDMN is intended to be a formalism for defining data models / items in a simple way (i.e. simpler than using UML), I would not expect it to contain classes that depend on anything in DMN. If DMN were being written now, I would suggest it would reference SDMN::ItemDefinition. If there are solid semantics for the split between SDMN::ItemDefinition and DMN::ItemDefinition, I would suggest they should be preserved by modelling both within SDMN, and making future versions of DMN refer to that.

The DMN form appears to model data items, rather than 'anything', which appears to be the scope of SDMN ItemDefinition. It is therefore not obvious to me that the inheritance is right. We might expect something more like:

ItemDefinition (abstract)
+--- DataItemDefinition (more or less the DMN version)
+--- XXXItemDefinition

where the XXXItemDefinition is various meta-classes representing e.g. document, class, - all the other kinds of itemKindRef, with appropriate meta-modelling attributes.