How to find the dates of vintage tarot decks

Maybe everyone already knows this, and I'm behind???
It's been a long 2 weeks of researching this for me. I am no expert on this subject, but I wanted to share what I learned. Hopefully, this can help someone out there.
TO BE CLEAR
If the publisher page has:
1978, 1983 and 1987 copyright
Printer key says:
109876543
It means you have a 3rd printing of a 1987 edition.
Of course, this applies to modern-day decks as well. The copyright date can help you narrow down what year the deck is or version especially when you get into higher printer keys. The copyright is updated when a change has been made, this is why we see multiple copyrights on a deck sometimes.
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