Just for the reference as I'm skimming through all the norms right now... There are many more symbols unsolved:
ISO 14405-1 specifies some "Specification modifiers", two letters enclosed in a rounded box.
Then there are annotation signs: a number inside a hexagon
Next ISO 1101:2017 specifies even more modifiers, more than OSIfont can handle: A, C, G, N, R, X are missing
Also interesting: the theoretical exact value (idk the exact translation, in German "theoretisch exakte Maße"), a value inside a rectangle
Then there are modifiers according to ISO 5459:2013, but these should be all in the osifont or are just letters in between of [].
Wouldn't it be possible to use diacritic characters to emulate all of those?
Some of those are actually possible:
https://en.wikipedia.org/wiki/Combining ... or_Symbols
So for example writing a
single letter inside a square is possible.
One possibility would be to extend osifont with the welding symbols as well as with diacritics for all those cases. But I guess that is a lot of work :/