> * Nested parentheses. (In theory, you could use any level needed (provided that they make sense), but in practice, they're scoffed at.) It is similar with quotes, for the same reasons: limited readability - although here you can at least juggle with single, double and French quotes, depending on the language and style guide used.

Any level of nested parenthesis is fine (is what I think at least (as someone who's written a bit of Lisp of Lisp (or Racket and Clojure specifically) (because you get kinda used to it (when in a way they just become invisible (or unnoticeable))))). But nested quotations is also an issue with backtick (`) when doing command substitution in the shell, and we have to resort to $() to fix it. There's not really a $()-like syntax for written English though.