Inline SVG generated from 4 digits describing forms (1|2 for line up/down:
unextended, ascended, descended, full height) of 4 bars as described for
example on <https://en.wikipedia.org?oldid=
670826999>.
This encoding developed by Royal Mail (identical to PostNL KIX-code)
restricts the 4⁴ combinations to exactly 2 ascenders and 2 descenders each
for 2⋅(4 nCr 2) = 36 characters.