There is a small number of cases with inconsistent parent information at the monthly level among children who were interviewed in separate households than their parent(s), but lived with those parent(s) for some months of the reference period. In these cases, the monthly parent identifiers (RPNPAR1_EHC or RPNPAR2_EHC) and monthly parent type (RPAR1TYP_EHC or RPAR2TYP_EHC) are missing, and the monthly relationship vector (RREL) should be used to identify parent-child relationships.