If the data sets match, MFJMATCH ends with a return code of 0. If the two data sets do not match, when the MFJMATCH utility finds the first mismatch it writes the two records that differ to a third data set (with asterisks under the columns that differ), then ends with a return code of 12. Records following the first mismatch are not compared.
If the data sets being compared are EBCDIC, the MFJMATCH utility also writes the hexadecimal representation.