Symmetry is broken between applicability and requirements due to nullness

It used to be that a facet was symmetrical. For example, a facet applied to an entity would result in either True or False. If you used that facet as an applicability True = applicable, False = not applicable. As a requirement, True = pass, False = fail.

I've noticed that the documentation has now changed such that this symmetry is broken. A facet used as an applicability seems to be always be treated as the "required" situation, whereas a facet used as a requirement has different meanings.

For example:
- Applicability (required): Property(pset=Pset_Foo, basename=Foobar) - Matches if Pset_Foo.Foobar is filled in
- Requirement (required): Property(pset=Pset_Foo, basename=Foobar) - Matches if Pset_Foo.Foobar exists, even if null

Another example:
- Applicability (prohibited): Property(pset=Pset_Foo, basename=Foobar) - Matches if Pset_Foo.Foobar is filled in
- Requirement (prohibited): Property(pset=Pset_Foo, basename=Foobar) - Matches if Pset_Foo.Foobar exists, even if null

Is this intentional? It acts as an edge case for users which can lead to surprise, and also means code is less straightforward to implement.