Quote:
Originally Posted by eschwartz
Well, you now know how to restore an ORIGINAL_FMT. 
As for why it is created -- calibre does not track multiple copies of the same format. However, the ORIGINAL_FMT facility is there for the one and only, sole purpose of helping you revert from a conversion gone wrong.
You can, of course, abuse that for other reasons.
But I will note that conversions always work from the ORIGINAL_FMT if one exists, and create a new FMT.
You are meant to delete the ORIGINAL_FMT once you verify the conversion worked.
You want to track revisions, invest in a Version Control System. 
Yes, we have had people requesting version control ("track changes") in calibre. |
Cool. I'm more interested in the multiple formats for things like PDFs or Txt files that have been optimized for certain devices rather than backup/version control. A book scanning service I use creates PDFs optimized for pc, ipad, and iphone but it appears I have to use a workaround like this one to get them into Calibre, for example, and I'll occasionally make some device specific formatting in a txt or epub. A second pdf or epub slot seems like it would be more useful than 95% of the obscure format slots calibre supports.