This value set includes codes based on the following rules:
http://snomed.info/sct
https://www.nlm.nih.gov/mesh
http://terminology.hl7.org/CodeSystem/icd9cm
http://terminology.hl7.org/CodeSystem/icd10
http://www.nlm.nih.gov/research/umls/rxnorm
http://hl7.org/fhir/sid/ndc
http://loinc.org