The UNINTGN option indicates how MFX’s BetterGener facility should process a non-VSAM uninitialized DASD SYSUT1 data set in a non-SMS environment. An uninitialized data set is one that has been created but never successfully opened and closed for output. In an SMS environment, uninitialized data sets are always processed as valid empty files.
UNINTGN=YES indicates that an uninitialized data set should be processed as an empty file. If an uninitialized multi-volume data set has the DS1IND80 and DS1IND02 flags off in the format-1 DSCB of the first volume and the number of data extents is non-zero, BetterGener will open the data set for output to set an end-of-file mark before the data set is used for input.
UNINTGN=NO indicates that BetterGener should terminate with a WER400A critical message if an uninitialized data set is provided as input on SYSUT1.
IEBGENER will treat an uninitialized data set as an empty data set. If you want to replicate this processing in BetterGener, set UNINTGN=YES. MFX (non-BetterGener) processing of uninitialized data sets can be separately controlled by the UNINTDS installation option.