There are two versions of the New. Super Mario Bros. for the Europe/PAL region. They seem to look exactly the same, except they both have a different secondary code.
The more common version has the code of NTR-A85P-EUR. Go to New Super Mario Bros. (A85P) (EUR) to view more information.
This is the more rarer version, but can still be found from time to time having the code of NTR-Y78P-EUR. Go to New Super Mario Bros. (Y78P) (EUR) for more information.