The document type and the ID/number identifying the referenced document. This example refers to an invoice number

COMEVE_Required
No
COMEVE_Examples
 <documentReference documentType="Invoice" id="1988744"> 
COMEVE_Xpath
/b24Message/communicationEvent/documentReference[@documentType="Invoice"]/@id
COMEVE_Type
Text
COMEVE_Sort
2000
COMEVE_Id
11