This value set includes codes based on the following rules:

• Include these codes as defined in http://terminology.hl7.org/CodeSystem/v2-0532 version HL7 v2.5

  Code	Display
  N	no

• Include these codes as defined in http://terminology.hl7.org/CodeSystem/v3-NullFlavor version 20090501

  Code	Display
  UNK	unknown

• Include these codes as defined in urn:oid:2.16.840.1.114222.4.5.274 version 20200526

  Code	Display
  PHC318	yes, carrier previously known to health department
  PHC317	yes, carrier previously unknown to HD
  PHC316	yes, unknown if carrier previously known to HD