[rgoddard]

{} means object [] means array So you would not be able to just drop them, since they mean two different things.

[sharkbrainguy]

for associative arrays foo: bar, for non-associative foo, bar,

surely this is unambiguous?

    x:
      y: "a",
      z: "23",
      q: 54,
         32,
         45
    ,
    r: 43