A fully missing imprint on the nib occurs on older Montblanc models from the 1960s to 1980s, e.g. on devices with hooded nib in which the engraving is only visible after disassembly. Current writing instruments, by contrast, should always have a visible nib engraving; where this is not the case, often a foreign nib was fitted, since the original nib would have to be replaced expensively. In the concrete picture example it is a Generation I model (Generation II has a broader cap ring) with a gold-plated steel nib actually belonging to the Classic. The Generation Classic, as a cartridge pen, has anyway no compulsory imprint. The hooded nib on the 31 is reachable by unscrewing the section.