This sort of practice goes back to BCPL, which wikipedia says is the first braced programming language. Because { and } weren't universally available, compilers

This sort of practice goes back to BCPL, which wikipedia says is the first braced programming language. Because { and } weren't universally available, compilers also supported the sequence $( and $) to represent these, which were typeable and printable on just about anything. https://en.wikipedia.org/wiki/BCPL https://en.wikipedia.org/wiki/BCPL This is the earliest example of this sort of thing i'm aware of - is there an earlier example? Also, BCPL supported // for comments, again, probably the first use of this sequence.