Clarification for properties in state "not set" required

I need clarification about how properties are handled in the getProperties() call which have the status "not set".
On the one hand side the spec states:

2.2.1.2.1 Properties
...
If a property filter specifies a property that is 'not set', it MUST be represented as a property element without a value element.

On the other hand side its stated for multi value properties:

2.1.2.1 Property
...
A multi-valued property is either set or not set in its entirety. An individual value of a multi-valued property MUST NOT be in an individual "value not set" state and hold a position in the list of values. An empty list of values MUST NOT be allowed.

My question is if properties with value 'not set' should be returned in a getProperties() call at all?

Martin