An example of extending your reserved list would be the world "lateral" (new type of join in 9.4). I'll do a PR if I get that far:}

RE: comments, yes it would be quoted and that would cause an error.

select/comment/ 1; ?column? ---------- 1 (1 row)

# "select/comment/" 1; ERROR: syntax error at or near ""select/comment/"" LINE 1: "select/comment/" 1;

That's probably a silly example, and I was just trying to think through 'what could go wrong with this?' before implementing. Thinking about it further, thats probably not something you want the library to be responsible for handling. I'd want to try out newline chars too since thats more common.