MOBI is a well-known e-book format. The popular Amazon AZW e-book is just based on MOBI. You can find many MOBI ebooks on the www.amazon.com. But one problem I ever met when reading MOBI e-book on Kindle Fire is that some MOBI ebooks don’t display in the “Books” category but “Docs” instead. This situation causes some inconvenience of managing a large number of ebooks as you have to browse in two different categories. Or just think about the scene that your favorite ebooks are mixed with some uncorrelated documents. It’s totally a mess! So it’s better to make MOBI files display as books on Kindle Fire, not docs.
Before we start, we should figure out why the MOBI books display in “Docs”. We know that the Docs category is used for storing personal documents like PDF, HTML, TXT or other documents sent by Amazon “Send to Kindle” service. Some MOBI ebooks are added personal document tag when generated so that the Kindle Fire will recognize them as documents but not ebooks.
After knowing this, you may ask “How about removing this personal document tag”? Yes, this is exactly we need to do. Calibre is the right tool for doing this job. It can convert MOBI to MOBI without quality loss and remove the personal document tag at the same time.
Download and install the latest Calibre on your PC.
Open Calibre and choose “Add book” to add MOBI ebooks. You can add more books at a time.
Select all books in the list and choose “Convert books”. Set the Output format as “MOBI”. Click “MOBI Output” at the left menu and find “Kindle Options” at right side. Delete the default “[PDOC]” and keep the Personal Doc Tag blank. Then click “OK” to start conversion.
Added by Chad Cloman: Amazon has changed things. It is no longer sufficient to just delete the [PDOC] tag. You must also add the [EBOK] tag (exactly as shown, with brackets).
You can see the conversion progress at the bottom right corner. When the number turns into “0”, the conversion job finishes. Click “Path : Click to open” to find the new MOBI e-book.
Connect your Kindle Fire to computer with USB cable. Transfer the MOBI file to the “Books” folder. Reject Kindle Fire and choose “Books”, you can find the MOBI book shows here. It’s no longer stay in “Docs”.
1. In our test we find that some MOBI ebooks can still display in “Books” even you don’t delete the “[PDOC]” but convert them with Calibre only. But I still suggest you replace the Personal Doc Tag with [EBOK] as this is more reliable.
2. You can also transfer the MOBI books to “Documents” folder of Kindle Fire and they can still display at “Books” (not Docs) as long as you’ve followed the tutorial. But for a better management, I suggest you put the MOBI books in the “Books” folder.