Do reserved words need to be quoted when set as property names of JavaScript objects?

Question

Given an object literal, or jQuery(html, attributes) object, does any specification state that reserved words, or future reserved words MUST be quoted?

Or, can, for

Answer 1

This answer cannot compete with those already given but I'd love to chime in nonetheless.

In my code I prefer to ALWAYS quote keys, for example:

var o;

o = {
  "label": "Hello",
  "index": 3
};

This way, the problem of strange names or reserved keywords doesn't even arise. Furthermore, all object literals are written in a style that is very near to valid JSON, as an added bonus copy+paste into a separate JSON file (and vice-versa) can be done very quickly.

Today, I consider this a must-have style for clean code.