[timtam]

Hi,

I would like Adding Books to have an option to "guess" ISBN from book metadata.

The logic could go like this:
If the option is selected and the book doesn't already have valid ISBN metadata, check if one of the TAGS is a valid ISBN (for a PDF file example, in the Keywords) and use that as book ISBN.

Can this feature be done easily?

P.S. Calibre is one of the best software I've ever used.