> >It's trivial for a computer to calculate that a 13-digit and 10-digit
> >ISBN are the same.
> 
> Assuming Kevin et al. know of the situation, and program for it.

There's actually a case for prodding the International ISBN Agency to update RFC 3187 so that that information is embedded in the URN representation. RFC 3187 predates 13 digit ISBNs. Some of the links and other information appear to be outdated too.

http://tools.ietf.org/html/rfc3187 

cheers
stuart