Originally Posted by capnm
How does it know the book is already on the device? While messing around with tweaking epubs I've ended up with some (but only some) duplicates on my reader -- and I haven't taken the time to figure out why ....
Is it the uuid in the metadata.opf file? (Except that a lot of my books don't have a metadata.opf file
what's up with that?)
If I tweak-epub, modify-epub, or convert, is it still the same book?
What if I copy it to another library?
There is a long discussion of how book matching works in the thread https://www.mobileread.com/forums/sho...d.php?t=134963