What's the row of numbers on the copyright page of books?
blogs.msdn.com
blogs.msdn.com
I used to work in a small town press and the local paper would employ the same idea for its editions. The first run, which I would deliver to the stores, was the two-star edition. After the first batch was done, the printer would go to the platen, erase one of the stars, and start the press run for the snail mail edition that would ship later to the customers who received copies by mail.
(edit: whoops, failed to read OP...but leaving here for the small press newspaper reference. Printers are interesting cats. You shall know them by their missing digits. No, not the numbers in the editionsm but the missing fingers lost between the rolling plates.)
Printing History:
May 2008: First Edition.
(Shakes fist) Damn you O'Reilly for making it so explicit. Next time, I want a puzzle! P3.0 printingThe edition number is always explicit, because for a new edition the pages are re-set. For a new printing the pages are (traditionally) not re-set, which is why the printing number has to be encoded in some manually-updatable way.
"It's unlikely that a single set of metal plates would survive multiple printings. They wear out pretty fast. Instead, this would be used on the film negative used to expose the photosensitive plates. Of course, now people are printing directly to the plates instead, skipping the film step." http://blogs.msdn.com/b/oldnewthing/archive/2007/04/10/20657...
The numbers aren't always reliable though... publishers can reprint multiple times and keep them as the same edition number. So, if you do want to purchase an early edition then do research on the book beforehand.