For easy understanding, am taking example of processing class 06 (Bring data from last pasyroll):
If processing class 06 is maintained for a wage type, it acts as per specifications
PRCL06 Specification -
0 - wage type will not be transferred from last PY period
1 - wage type amount is brought from last PY period to current period
2 - w.t will be taken from previous PY period, if it belongs to same year Ex: Annual Perk Exem.,
Hope this helps