How does Retro Pay calc process handle a check that has been reversed and the reversal check?

When the retro calc process is run, does the process ignore checks where the PAYCHECK_STATUS=R or where the PAYCHECK_STATUS=F and the PAYCHECK_OPTION=R or does the program process both (they would next to zero).  Also if a check was previously used to calculate a retro payment that was paid and then that check was reversed - is anything triggered (like a negative retro)?