Tuesday, September 27, 2005

Then why?

I discovered it is possible to type in just the 1st 9 digits of an ISBN- leave off the last digit, x or not. If this is true (no exceptions found yet), then why is it necessary to have 10 digits in an ISBN?

3 comments:

the stealthy librarian said...

Hey, I have had the same experience. At first I thought it was just on ISBNs that ended with x, but then I accidentally did it on some others and it worked that way too. What databases were you doing that in? I have done it in Amazon & LOC.

The Liberry aka Amy said...

Baker and Taylor Title Source, III, Amazon, anywhere else!

Phil Ringnalda said...

The last digit is a check-digit, calculated from the first nine to make sure nothing got swapped or typoed (0-7432-7694-9 is a valid ISBN, 0-7432-7649-9 isn't), but for things where a typo won't order twenty cases of the wrong book, you can quite often leave it (or even more) off, without losing any precision.

III will actually take as little of the number as you want to give it, so for smallish publishers you can see, for instance, everything you have published by Ten Speed by searching for 089815 and 158008 (and possibly another prefix or two I haven't seen).