@User yes, if you specify W, L and mult, the netlister assigns calculated values to the other parameters, ad, as, pd, ps, nrd, nrs. the ad, as, pd, ps are for parasitic diodes (capacitances) , while nrs and nrd are for calculating drain and source resistances. Of course if you have the real layout you should put the actual values not the calculated ones which assume a drain/source extension from gate edge of 0.29um