-GOP - Generic Output Profiling
GOP stays for 'Generic Output Profiling'. It is a patented solution to create new ICC profiles by exchanging color channels in existing ICC output profiles. This is currently possible for multi-color profiles, and will soon be possible for CMYK profiles in PM5.
To exchange a color in a profile, at minimum, the media white point and the full-tone color need to be measured in the GOP dialog. Ideally, a printed gradation wedge of the new color is also available for measuring.