Thanks for the input and for pointing out the typos. They are fixed now. I will consider changing the invert flag, but I'm not that happy with something like "

Thanks for the input and for pointing out the typos. They are fixed now. I will consider changing the invert flag, but I'm not that happy with something like "--list=...". There will be only two modes with discard being the default one. So imho there should be only one flag to switch to the non-default mode.