Manually at add time using a custom column (#Master_Format)
EPUB is a good 'Master' to start with (I believe there is a Preferred format list somewhere in the FAQ)
The Quality check PI can do some checks, but so many things can leave a Calibre
fingerprint on the book (including the publisher)
Your OS
might help YOU see it (but not get the info into Calibre without a bit of programming on your part)
WXP CLI example (help DIR to see other CLI switches)
Code:
T:\Users\Shared>dir /s/tc IntakeLib