IHE PCC - Internal References (warnings) Checks wheter the CDA structure is conformant to the IHE PCC - Internal References IHE PCC - Internal References (warnings) Verifies the structure of a IHE PCC - Internal References In IHE PCC Internal References (1.3.6.1.4.1.19376.1.5.3.1.4.4.1), if the element referenced by an Internal Reference does not have a <code> element, then the nullFlavor attribute should be set to "NA". Successfully tested: In IHE PCC Internal References (1.3.6.1.4.1.19376.1.5.3.1.4.4.1), if the element referenced by an Internal Reference does not have a <code> element, then the nullFlavor attribute should be set to "NA".