This code system http://terminology.hl7.org/CodeSystem/ex-diagnosis-on-admission defines the following codes:

CodeDisplayDefinition
yes YesDiagnosis was present at time of inpatient admission.
no NoDiagnosis was not present at time of inpatient admission.
unknown UnknownNot known if condition was present at the time of inpatient admission.
 <status value="draft"/> <experimental value="false"/> <date value="2022-09-14T03:23:03-06:00"/> <publisher value="Financial Management"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> </contact> <description value="This value set includes example Diagnosis on Admission codes."/> <copyright value="This is an example set."/> <caseSensitive value="true"/> <valueSet value="http://terminology.hl7.org/ValueSet/ex-diagnosis-on-admission"/> <content value="complete"/> <concept> <code value="yes"/> <display value="Yes"/> <definition value="Diagnosis was present at time of inpatient admission."/> </concept> <concept> <code value="no"/> <display value="No"/> <definition value="Diagnosis was not present at time of inpatient admission."/> </concept> <concept> <code value="unknown"/> <display value="Unknown"/> <definition value="Not known if condition was present at the time of inpatient admission."/> </concept> </CodeSystem>