History of trailing comma in programming language grammars

Question

Many programming languages allow trailing commas in their grammar following the last item in a list. Supposedly this was done to simplify automatic code generation, which is

Answer 1

I'm not an expert on the commas, but I know that standard Pascal was very persnickity about semi-colons being statement separators, not terminators. That meant you had to be very very careful about where you put one if you didn't want to get yelled at by the compiler.

Later Pascal-esque languages (C, Modula-2, Ada, etc.) had their standards written to accept the odd extra semicolon without behaving like you'd just peed in the cake mix.