This is the ValueSet that contains all the codes in LOINC Codes (http://hl7.org/fhir/ValueSet/observation-codes) and BSeR Telcom Communication Preferences VS (http://hl7.org/fhir/us/bser/ValueSet/BSeR-TelcomCommunicationPreferencesVS). E.g. what you have to deal with if you get resources containing codes in either of them