The long option shouldn't be --kilobyte, since ls -k means 1024 not 1000. So I suppose it should be --kibibyte.
It's a little tricky, since -k means --block-size=1K for df and du as well, and I assume this won't change, since df -k and du -k conform to POSIX. (Surely there's no need to add --kibibyte to du and df -- why should we make df and du more confusing merely because ls must be more confusing? :-). So does the following sound plausible? Add --kibibyte to 'ls', make it equivalent to -k, change -k so that it conforms to POSIX, and have --block-size override -k. But leave df and du alone
