These cases might be in violation of the specification, but since all these fields may have a safe default (i.e. the empty case), it is trivial to support their absence.
I copied the warning behaviour from the fields that already might be absent (e.g. objects).
These cases might be in violation of the specification, but since all these fields may have a safe default (i.e. the empty case), it is trivial to support their absence.
I copied the warning behaviour from the fields that already might be absent (e.g. objects).