I found something I didn’t expect when I defined an enumerated Conceptual Domain (CD) and linked it to an enumerated Value Domain (VD). I wasn’t expecting that I could only define the meaning of Permissible and Supplementary Values of the VD by linking them to CD Values. For example, I can’t define a Value Meaning for “8” unless I define it in the CD and link to it.
I expect there will be cases where the Permissible Values in the VD are different to the Values in the CD (especially when developing metadata using methods like #mast that @sam just announced). For example, the Permissible Values in the VD may not have been harmonised with standards represented by the CD. However, there can still be significant benefits to linking the CD to the VD to aid discoverability and also make it clear where the VDs need to be harmonised.
I don’t think that Supplementary Values in the VD should need to link to Values in order for the meaning to be defined. Supplementary Values (e.g. Not Stated, Not Determined) are often have very specific meanings based on how the data was collected and processed (e.g. Not Stated could have different meanings in different data sets).