Classics Illustrated 23 August 1964 is not listed in CLZ. Please add details and values.
Hi, do you have the HRN for me? I cannot add it with just that date.
What’s HRN?
I commented on the big thread with an explanation. I’ll be happy to help you identifying your printing.
I read your explanation;
“Oh, I’ll explain it to you. It’s the “Highest Reorder Number”, these titles were often reprinted and the highest number in a list that could often be found either on the inside or on the back. The highest issue number on that list corresponds to the printing of that specific issue you have in your hand.
Example:
This book has #136 as the highest number so that would correspond with the “14th Printing”. There are tons of printings for each title in this series. Checking for that number helps you in identifying which one you own or which I should add for you 
If you have any questions or need help identifying which one you own, please let me know!”
My reply;
The back of this book’s highest issue number is 167, but the inside of the cover states it’s August 1964. Isn’t this the actual date of the book??
Well yes, but sometimes different printing numbers have the same cover date (the date you mentioned). The 13th print, 14th print and 15th print all share the same HRN. The dates aren’t always correct online, but in your case this would be the 14th printing.
Wow, so even though the date on the inside of the cover states the book is August 1964, you are saying that information is just a copied page from the first printing?
In other words, they copied that inside page exactly as it was printed August 1964 and they did not specify anywhere in the book like they do today letting a person buying it know that it’s a reprint?
And the only way we have of knowing today what we’re holding is by the HRN on the back of the book?
Yes, but not always. It doesn’t with the date you mentioned but I can show you an example where it does. So that HRN number is the only lead you have (in your case along with the cover date) in identifying what printing you own.
Here I found what looks to be the 7th Printing. The cover date is the date of the original release but the HRN is 94. Never mentioned anywhere inside the book that it’s a reprint. I guess when you see a series that has been going for so long at that time that has been running 94 issues before yours, it’s kind of obvious that it’s a reprint. But yeh, there’s no way of knowing and they’re not making it easy 
All of the different printings have been added to #23. If you any other issues from this series that need to be added, feel free to drop them here.