...
Oil – WTI
Oil – Brent
Copper
We may not represent all of these outright, but this list provides the primary ones we should consider representing, as individuals, including having some representative examples of the values of at least some of them at some point in time so that people using the ontology can understand how to use the ontology to manage this sort of information. The goal is to reference the definitive source of the information so that someone can automate populating it as needed for their internal purposes.