The following applies if you are using a version of the software before Update 23. For the latest information, see Propagate reason for rejection.
Process class name: PropagateProperty
Arg1: OBJ is a prefix that means current object. SCLBProjComsResponseRejectReason is the property definition that populates the comments.
Arg2: SPFStepComments is the step where comments are provided from the source.
Using the keyword PREVIOUSINTERACTIVE as an argument reverts to the previous step in the workflow where user interaction is required for signing off the step.