Upright letterforms with rounded corners for technical drawing, as defined in the German industry standard, DIN, in 1938. [Pool]
Berthold Fototypes offered both DIN 17 and the inclined DIN 16. [Gorissen 1974] So did Letraset. [1969 leaflet] In or before 1975, Letraset later added a second weight: DIN 17m (for Micronorm) is lighter, slightly wider, and distinguished by a monocular ‘a’. See also Normalisé Din (Mecanorma, 1968).