The subject term is distributed if the proposition is universal
(A or E) and undistributed if the proposition is particular (I or
A statement about all Ss obviously makes a claim about the whole
class, so S in this case is distributed. Just as obviously, a
statement about some Ss does not make such a claim, so S in this
second case is undistributed.
Similarly, "No S is P" says something about the entire class of
Ss, so that the subject is distributed. "Some S are not P" does
not cover all the Ss, so the subject there is undistributed.
For the subject term, what matters is quantity. Quality is