  This article proposes the axiomatizations of contingency logics of various
natural classes of neighborhood frames. In particular, by defining a suitable
canonical neighborhood function, we give sound and complete axiomatizations of
monotone contingency logic and regular contingency logic, thereby answering two
open questions raised by Bakhtiari, van Ditmarsch, and Hansen. The canonical
function is inspired by a function proposed by Kuhn in~1995. We show that
Kuhn's function is actually equal to a related function originally given by
Humberstone.
