Assume that there are four data sets, all with associated correction files already defined, either by default in their PHA file, or explicitly by using the corfile command.
XSPEC> cornorm 1-4 1. ! The correction norm for all four is set to 1.0.XSPEC> cornorm 0. 1-2 0.3 ! The correction norm for the last input range (which was 1-4) is set to 0., then files 1 and 2 are reset to 0.3.
XSPEC> cornorm 4 ! File 4 has the correction also set to 0.3.
XSPEC> cornorm 1 4 -.3 ! Files 1 and 4 are set to -.3.
XSPEC> cornorm .7 ! File 4 (as the last input single range) is set to 0.7.