I found on the Wikipedia page that "pi matrices" referred to all the gylphs that didn't have their own key, due to rare usage. Fractions, foreign letters, pres

I found on the Wikipedia page that "pi matrices" referred to all the gylphs that didn't have their own key, due to rare usage. Fractions, foreign letters, presumably £ for the American machine shown. https://en.wikipedia.org/wiki/Linotype_machine#Pi_matrices https://en.wikipedia.org/wiki/Linotype_machine#Pi_matrices