Re: Newbie question

On Thu, 23 Jun 2005 01:00:21 +0200, mAsterdam <mAsterdam_at_vrijdag.org> wrote:

[snip]

>One practical low-redundancy check is the eleven-proof
>on dutch (postbank did not join) bank-accounts, position
>from right to left:
>
> ( (sum(position * digit)) mod 11 = 0
>
>with 10 digits or less, this garantuees malformed numbers whenever:
>1 digit is mistyped
>1 digit is inserted
>2 digits changed places,
>all very common typos.
>When 2 or more digits are mistyped, there is a chance of 1/11 that the
>string is well-formed.

     That is very similar to the ISBN validation. It might even be the same if the check digit is in position 1 and the value used for 10 is "X".

Sincerely,

Gene Wirchenko Received on Wed Jun 22 2005 - 18:12:41 CDT