Unique Records

Hi All

I am wondering what constitues a “unique” record when Book Collector checks. For example, when I add a book through the ISBN search, Book Collector will advise me that I already have this title

What is that check based on? I tried adding a book manually - using an ISBN # and Title (and author) that all exist in my collection and it provided no warning

My reason is that I am considering using Book Collector to catalogue my RPG collection. While Book Collector has come a long way in having RPG books in their “library”, I would still have to add a lot manually. Is there a way I can try an avoid duplicates?

I could produce the list in a spreadsheet and filter the unique records but this isn’t efficient if I am only adding a single book

Thanks