While I think that “paper” was probably funnier in its authors’ heads, there is some actual precedence: Atlas Autocode used underlining to distinguish user-defi

While I think that “paper” was probably funnier in its authors’ heads, there is some actual precedence: Atlas Autocode used underlining to distinguish user-defined identifiers from the language’s own keywords. https://en.wikipedia.org/wiki/Atlas_Autocode https://en.wikipedia.org/wiki/Atlas_Autocode