JSON-to-RON encoding

[cblp]

I know, JSON is here just for an illustration, but this is inconsistent.

There are 2 JSON example in the Spec.

Example 1.

*lww #1TUAQ+gritzko @`   :bar = 1
     #(R            @`   :foo > (Q

Problems

1. The Spec says header is mandatory.
   If these are raw ops, then semicolons must present.
   If reduced, then a header must present.

2. From example 2 one may conclude that you must create and empty dictionary
   before filling its fields. There is no empty object op here.

Example 2.

*lww #1D4ICC+XU5eRJ @1D4ICCE+XU5eRJ :0       !
*lww #1D4ICC+XU5eRJ @1D4ICCE+XU5eRJ :keyA    'valueA'
*lww #1D4ICC+XU5eRJ @1D4ICC1+XU5eRJ :keyB    'valueB'

Problem

How can a reader know this object is a dictionary (JSON object)?
Just because the fields are filled with values? What about an empty dictionary?
Does its encoding differ from null?

Just question: what is the purpose of the header? Declaration of the object?
Must it be the root op?

[cblp]

@gritzko:
header содержит метаданные редукции
которые могут быть нужны при следующей редукции