There's clear information on specific changes that merit "each card" a "change"

It illustrates which backs were used on which cards

It identifies which Diamond(s) REALLY go with which Golds and Plats

And believe it or not... there only something like 20 "real variations" of cards
... (of course, there were a half dozen cards issued in each variation

AND if you pick it up in PERSON - and you seem confused and overwhelmed... Janice MIGHT take pity on you (like she did me) and throw in a little "Slotcards for Dummies, aka How the Book Works"

But add some cookies, a soda AND a free Nevada obsolete from Jerry ... it's the Best Book Bargain in Las Vegas!!"