No mystery here: this typeface is based on Edward Johnston’s 1916 design for the London Underground and, more specifically, as it was employed in posters boosting The Tube. To implement “lowercase” numbers, refer to the PDF character map, or activate Stylistic Set 1 in OpenType-aware applications. Both versions include the complete Unicode Latin 1252, Central European 1250 and Turkish 1254 character sets, as well as localization for Lithuanian, Moldovan and Romanian.