Made as simple as possible, but not simpler.
Good identifiers are opaque, so translation is by association – owl:sameAs, skos:exactMatch, or some other relationship.
Where do you look for identifiers? If you’re looking for a URI, the IANA has a registry of schemes, like https, mailto, and tel.
How do you validate that an identifier service provides global uniqueness of minted keys, persistence of bindings, and resolution of keys to descriptive metadata?
Day 1 of my five-week experiment to elaborate on FAIR-enabling services, and I already find myself fallen flat on my face.