The Consumer Real-time Pharmacy Benefit Check (RTPBC) IG client system is a mobile consumer application, which will typically not know the primary language of the user. The US Core Patient profile sets communication.language as Must Support, which presents an obstacle to using the US Core Patient in the Consumer RTPBC IG.

The proposed RTPBC Patient profile below does not set the communication.language element as Must Support, because it will typically not be known with certainty by the IG's participants and the information is not pertinent to the IG's use case.

http://build.fhir.org/ig/HL7/carin-rtpbc/StructureDefinition-rtpbc-patient.html