  Let p be a rational prime, k be a perfect field of characteristic p and K be
a finite totally ramified extension of the fraction field of the Witt ring of
k. Let G be a finite flat commutative group scheme over O_K killed by some
p-power. In this paper, we prove a description of ramification subgroups of G
via the Breuil-Kisin classification, generalizing the author's previous result
on the case where G is killed by p>2. As an application, we also prove that the
higher canonical subgroup of a level n truncated Barsotti-Tate group G over O_K
coincides with lower ramification subgroups of G if the Hodge height of G is
less than (p-1)/p^n.
