Originally Posted by itimpi
HTML is the best format for conversion, so if you have that available use it for the conversion.
As I said, HTML is my source format, PDF is the converted format... But I don't want to add the HTML + epub + mobi + PDF files. I don't like the fact that Calibre makes a copy of each book. I was just exploring if I could use Calibre to keep track of the books on my devices. I don't use the GUI to convert, the only conversion I use is by command-line (from mobi to HTML, the rest I do using my own tools).