[rudian]

You can turn any piece of a YAML into a JSON object and it will be read just as well.

This YAML:

    user:
      name: Ted

is equivalent to this YAML:

    user: {"name": "Ted"}

which is equivalent to this YAML/JSON:

    {"user": {"name": "Ted"}}

[Spivak]

While true, this is what being a supperset means. What it means is that any JSON document is, without modification, valid YAML document and can be read with a YAML parser.

[Izkata]

I think you mean "this isn't what".

[andoriyu]

That's exactly the case. Any YAML 1.2 parser can parse any valid json document as is.

[erik_seaberg]

YAML supports tagged nodes and multiple documents in a stream, which can’t be represented in standard JSON. (You could make up conventions, but only your parser would support them.)