The International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), describes the classification of morbidity and mortality information for statistical purposes and for the indexing of healthcare records by diseases. The ICD-10-CM codes can be used as the value of the Act.cd attribute.
This code system http://hl7.org/fhir/sid/icd-10-cm defines many codes, but they are not represented here