This code system http://hl7.org/fhir/account-relationship defines the following codes:

CodeDisplay
parent Parent
guarantor Guarantor
<status value="active"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><description value="Relationship between accounts"/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/account-relationship"/><content value="complete"/><concept><code value="parent"/><display value="Parent"/></concept><concept><code value="guarantor"/><display value="Guarantor"/></concept></CodeSystem>