$ icclink -v -l 280 -kt ISOcoated.icc ISOuncoated.icc ISOlink4.icc
Am I wrong with it?
You need to select -G to enable -kt to work. It would be safer to select a gamut mapping mode to go with it too (e.g. -i0 ?). Note that the command line parser will get confused if -G is the last option before the filename, it won't know if the following filename is the source icc or the optional source gamut file, so make a habit of putting -g or -G near the start of the command line.
[I will see about making icclink a little smarter in automatically selecting a mapping mode to suite the selected options in the next release. ]