[EbokJunkie]

Thanks, but how to preserve fake margins via command line interface? I work only by command line and mobi ouput option "--mobi-ignore-margins" doesn't work.
Documentation wording is very unclear on this option:
"Ignore margins in the input document. If False, then the MOBI output plugin will try to convert margins specified in the input document, otherwise it will ignore them"
What False means? This option doesn't seem to accept any parameter values?
Just using this option still results in removing my margins.
Update:
Followed Doctor Ohh advice, unchecked option Remove fake margins in GUI and tried conversion to mobi (both). Result: no negative margins applied.
Interesting that kindlegen respects my addition of negative margins (I do this under tag *{}) but Calibre still kills them.