You are correct sir!
Publishers will speculate how many times they are going to print a book. They then put the numbers in the front of the book corresponding to the number of print runs they plan to make, striking off the first one for each print run.
Ten seems to be a very popular number, probably because they seldom have that many printings and they don't have to worry about running out of numbers.
For example. I'm going to print a book, it will be extremely popular, so I plan to do 10 printings of it.
1 2 3 4 5 6 7 8 9 10
I strike off the first number for the first printing so the first run would look like this
2 3 4 5 6 7 8 9 10
The next run would look like this
3 4 5 6 7 8 9 10
Etc.
The second printing of T20 looks like this
3 4 5 6 7 8 9 10
I know, cause I got one!
Don't confuse printing with edition, or versions.
If the changes are too numerous or too large in scope, a new edition will generally be issued. This new edition may have numerous printings. The first would be
2 3 4 5 6 7 8 9 10
The corrections incorporated into print runs are usually of a nature related to technical problems (a page inserted upside down) or typos (errata), etc. Minor problems.
A major rules change would probably warrant a new edition.
Hope that helps.
Later.
Greg.