Why does the CLASSWKR variable suppress private, non-profit on the ASEC data but not the monthly files?

The CLASSWKR variable on the 2015 ASEC file suppresses the private, non-profit category, but the monthly 2015 CPS CLASSWKR variable does not. I typically use the ASEC data, can I merge one month of the monthly file with the CLASSWKR variable onto the ASEC? How would I do this? i.e., what variable would link the monthly CPS to the ASEC?

Thanks,

–Kristin Smith