Re: Looking for comments

Thomas SMETS wrote:
> 
> <snip>
> ISBN's have a checkdigit; it would be sensible to provide a
> function to be used in a CHECK constraint to ensure that the
> ISBN is valid.
> </snip>

Here's a URL with more
information:http://www.isbn.spk-berlin.de/html/userman/usm4.htm.

I've written a similar algorithm in C to create and verify checksums for
eight digit codes.  The final code is then 9 digits.  I did this to help
create codes that are the same length as a social security number.  If
you'd like a copy, let me know.

-Ron-