heres a more recent groff implementation of it the macros: https://linux.die.net/man/7/groff_ms prob not what you're looking for, you prob want to get ahold of the orig nroff/troff files

the implication for me at least is a lot, and yeah a lot more has come to exist since so shrug still nothing like using a troff/nroff from 1984 I spose