> > That may be so but it misses the point. The point is there is a field, > be it a URI or a literal however modelled, that can be used to join > between two datasets. This join field is "hidden" in that there exists > no (known) dataset that contains all possible values it can take on. >
Hmm. I'm still not getting why this is a problem. It seems like as long as the ISSNs in both datasets are represented by nodes with type-assignments, all you have to assert is that the two types are equivalent (e.g. same URIs, or owl:equivalentClass...), and that their rdfs:labels uniquely define them (e.g. owl:InverseFunctionalProperty...). I don't (yet) see why you need an imaginary extra dataset in between.
