https://www.ibm.com/docs/en/ims-rcvsolutionpack/2.1.0?topic=oicds-using-stack-keyword-stacking-image-copy-data-sets
Using the STACK keyword (stacking image copy data sets)
If the STACK keyword is specified, output image copy data sets are created as stacked data sets.
the stackkeyword stackingusingimagecopy