How to reference the semantic ID of a value list in a property

[JS-Aibel]

Description
In classification systems like IEC CDD, properties can have a value list (enumeration).
The enumerations covered by the IEC 61360 data specification only define each element in the value list.
We are looking for a way to store a reference to the value list ID itself, so we do not have to explicitly include all the individual enum elements in each Concept Description.

Questions

1. Are there any existing methods to store the semantic ID of the value list itself?
2. In this Q&A entry, what is meant by:

The IRDI of the value list itself should be used in submodel template definitions to restrict the allowed string values.

Possible Solutions

• Extend DataSpecificationIEC61360 to include an attribute for the value list code (as defined in CDD).
• Extend the DataSpecificationIEC61360 data type attribute with an element like ENUM_STRING_TYPE(<ID>).
• Use qualifiers with a semantic meaning of “allowed value list” and set it to the IRDI of the IEC CDD value list.

[StenGruener]

hi,

we checked, and also referring to the list is not mentioned in ECLASS-AAS document here: https://industrialdigitaltwin.org/en/wp-content/uploads/sites/2/2024/10/2024-10_IDTA_ECLASS_Semantic_Transport_ECLASS_in_AAS_1.0.pdf

We believe that qualifier should be the "last resort".

[StenGruener]

@BirgitBoss hi Birgit, would it be a discussion for the meta-model working group?

[BirgitBoss]

I do not see the need for a " reference to the value list ID itself, ": this is part of the property CD definition anyway, so why not look it up there?
Only if the single values shall be documented as well then a value list as defined in https://industrialdigitaltwin.io/aas-specifications/IDTA-01003-a/v3.1.1/specification.html#value-list-attributes can be used

What is not supported by AAS so far are value lists with implicit values only. Only explicit values are allowed.

since there are many questions w.r.t. values in CDs I suggest to add a corresponding questions-answer to document what IS possible

But yes, if a metamodel change is required then please add an issue here:
https://github.com/admin-shell-io/aas-specs-metamodel