Escaping is weird. Why ~0 and ~1 instead of \ and \\ ? Also

> Finally, if you need to refer to the end of an array you can use - instead of an index. For example, to refer to the end of the array of biscuits above you would use /biscuits/-

how do you refer to "this value" in this example?

    {
       "biscuits": {
           "-": "this value"
           "zzzz": "something else"
       }
    }