Pilot's catalogue numbers can actually be read — but the same letter means different colours on different pens
Fountain pen catalogue numbers are usually a run of digits that tells you nothing. Pilot is the exception. Both colour and nib are spelled in letters.
So they can be read. They can — but there is a trap.
The colour is the first letter of the colour name
A Pilot number sets out the model and material first, then appends letters for colour and nib.
The colour letter is usually the initial of the colour's name. On the Kakuno, grey, soft pink and soft blue each take their own initial. On the Custom Urushi, deep black and vermilion take one letter each.
There is even a code for having no colour. The Custom Heritage 92 uses one meaning "non-colour" — the barrel is clear, so there is nothing to paint.
Here is the trap: the same letter, a different colour
It looks readable, but there is no fixed lookup table.
The same letter denotes different colours on different models. B may be plain black on one pen and deep lacquer black — a different colour name entirely — on another. Once you build a code from initials, that follows automatically.
So Pilot numbers are not so much readable as readable *if you already know that model's colour names*.
Soft nibs get a mark of their own
Extra fine, fine, medium, broad and double broad are shared vocabulary across the industry.
What is distinctive at Pilot is the Elabo, where an extra letter is prefixed to the nib code. The pen is sold on the softness of its nib, and that softness has been given a code of its own. Few brands put feel, rather than just width, into the number.
Pilot also offers a fine-medium, sitting between fine and medium, written as a combined code.
The same number does not always mean the same pen
One thing the number can never tell you: pens sharing a catalogue number can differ by production period.
PencilDB records this separately, as a "generation". The string alone will not reveal it. Older discontinued models may not follow the pattern described here at all.
(Compiled from the Pilot fountain pens recorded in PencilDB, August 2026.)