Excellent to see that OpenFDA features harmonization on identifiers as annotated strings http://open.fda.gov/api/reference/ How about http-based URIs as a next step? As part of applying the LinkedData principles, see http://kerfors.blogspot.se/2014/04/openfda.html for links to examples such as LinkedAERS and Linked SPL and to experts in W3C HCLS and Bio2RDF