On making a font with 9,999 ligatures to display thirteenth-century monk numerals. Cistercian monks could write any number 1–9,999 as a single glyph: four quadrants of strokes around a vertical staff, one per decimal place. The clever bit here is abusing OpenType ligatures to render them — type “1485” and the font assembles the right strokes automatically. 9,999 ligature rules is absurd, but the system is so regular they can all be generated programmatically.