Only Montblanc knows the exact coding of the serial numbers; deviations from the 'two letters + seven digits' scheme do therefore not automatically mean a counterfeit. Indications like inscriptions 'Made in Germany Metal' in the clip and 'Box made in China' on the case bottom are usual on originals. If the serial numbers are engraved instead of embossed, this should, however, be checked more closely. On ballpoints authenticity check without inspection in a boutique is fundamentally more difficult than on fountain pens.