Processing "incomplete triples" when direction is "none"

In RDFa Core 1.1, Section 7.5, Step 12 (completing "incomplete triples"
passed down from the parent element):

There is a statement that say's: "If direction is ’none’, the new subject
is added to the list from the iterated incomplete triple." I cannot figure
out what that means.  OK, I know the direction would have been set to
"none" if the incomplete triple was originally created in an element
containing @inlist (per Step 10). However:

A) I don't get the point of the whole procedure.

B) Which list are you talking about?

C) By "iterated incomplete triple" do you mean the incomplete triple you
are processing right now?

C.1) If so: how can an "incomplete triple" - which is actually just a
predicate with a direction - even have a "list"?

C.2) How would it ever be appropriate to put a "resource IRI" into a list
for "predicate IRIs"?

Unless ...
Do you mean that the predicate from the "incomplete triple" should be added
to what you folks call the "local list mapping" (if it isn't already there)
and then the [new subject] should be added to the list associated with that
triple, as per the normal processing for @inlist list items?

Is the point of this whole process to defer actually adding to the "list
associated with the predicate" until you have a [new subject] from a child
element that can be treated as an object for that "incomplete @inlist list
item" from that child's parent?