The service guide provides for two different numbers. What Montblanc calls the ident or model number is the article number — 146 in the case of the Meisterstück LeGrand. The individual number, by contrast, means the serial number of the particular pen; it is applied by laser engraving on the ring of the clip and, on newer pens, begins with two letters.
In practice many dealers leave the individual-number field blank or enter the article number there instead. That is not a mistake: for proof of guarantee, the date of purchase, the model name and the shop's stamp or sticker are enough. The serial number, laborious to read even with a loupe, is only needed if a claim actually arises, and that applies to a small proportion of the pens sold. A service booklet showing the model number under the individual number is therefore no sign of a tampered-with or inauthentic pen. Conversely, the laser engraving on the clip ring is one of the features regularly consulted when authenticity is being checked.