This is the ValueSet that contains codes in both US Core Common substances for allergy and intolerance documentation including refutations (http://hl7.org/fhir/us/core/ValueSet/us-core-allergy-substance) and Common substances for allergy and intolerance documentation including refutations (http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1186.8).