i am processing these records by adding SEQNUM (at offset say 500) for certain overlay and arithmetic operations. Therefore the output records will now have RDW 500+. Is it possible to have my output with original RDW?? i know that i can use the first 8 byte record identifiers to set the length using OUTREC IFTHEN BUILD. but can i do this dynamically using the RDW from the input record rather than record identifiers?? The file has more than 90 types of records with their own lengths. If any application program changes any length, i do not think they will be able to easily find the impact on this SYSIN card.