If Tom's proposal for dictionary is accepted, then I suggest
that it be described
a) in the model document: "a dictionary consists of a collection zero or
more attributes (name and value pairs)"
b) in the protocol document: "an octet string whose syntax is
'attribute-sequence'. The value-length is number of octets in the
entire attribute-sequence contained in the value"
I think that this language suffices to define it.
The protocol document should also contain an example.