Specifies the prolog version number of the output indexed file. Format /PROLOG=n Specifies the prolog number 1, 2, or 3. If you specify 2 for n, the output file will be either a Prolog 1 or a Prolog 2 file. If you specify 3, the Convert utility creates a Prolog 3 file for output. Prolog 3 files accept multiple keys (or alternate keys), all data types, and segmented keys. The only restriction to using a Prolog 3 file applies to files containing overlapping key segments for the primary key. In this case, you would have to use a Prolog 2 file. If you do not specify the /PROLOG qualifier, the Convert utility uses the prolog version of the first input file. If the input file is not indexed, the utility uses the RMS default. To see what this default is on your system, enter the DCL command SHOW RMS_DEFAULT. The /PROLOG qualifier overrides the value given with the FDL attribute KEY PROLOG.