Before revision: In the (common) case that the analog transfer function has more poles than zeros, the zeros at may optionally be shifted down to the Nyquist frequency by putting them at , dropping off like the bilinear transform (BLT).
After revision: In the (common) case that the analog transfer function has more poles than zeros, the zeros at may optionally be shifted down to the Nyquist frequency by putting them at , causing the transfer function to drop off as in much the same manner as with the bilinear transform (BLT).