Unscanable! An unscanable!
Book collectors depend on bibliographies that catalog publications and their print runs, sometimes providing detail on identifying features (like spelling mistakes fixed in later editions). Most bibliographies focus on a specific niche, era, or even an especially large collection. For particularly interesting books, provenance is often just as important as with artifacts.
There’s something about having to pour over paper bibliographies to identify first editions by spelling mistakes and print errors that really separates the wheat from the chaff.
It truly is fun. In my case, it's trolling through old biographies of a minority language, hunting down authors names and then the names of their books. But it's great fun as often there's never been a complete list of these works compiled, so I'm sorta now the go-to person for a specific dialect region with regards to books by authors of the region.
My particular specialty is pre-Standard books written by authors from Conamara, in Ireland. I'm at the point where I have most of the first editions I know about from before the standard, with only three, at most (I need to get to a library to compare editions of one, as I think I have the school edition but am not sure if the school was the first edition published), eluding me. Then I'll branch out into other, similar dialectal regions.
It's so fun hitting up used bookshops for books in another language, and types of books like that. I'm kinda looking forward to expanding my dialectal region as it'll allow me to basically start the hunt all over again.