RESETThe RESET option allows you to prevent VSAM from treating an output file as a DISP=MOD data set if the output VSAM file was created using the REUSE option.
To prevent this type of VSAM processing, specify RESET. If REUSE was not specified when the data set was created, the RESET specification will be ignored and the data set will have output performed to it in a DISP=MOD fashion.
The default is to treat all VSAM output files as DISP=MOD data sets by not specifying RESET.