It's just an idea, and a tiny one at that, but I was momentarily perplexed by the lines like -n, --lines=[-]K in head --help, making it look like the number is given in kilobytes, when I knew that was not correct :).
So I suggest replacing K with N in the --help messages when the metavar is standing for just a number, especially/only a number that takes a suffix. FWIW ... --best, karl.
