  In this letter, we study systematically the general properties of the
$B$-extension of any integrable model. In addition to discussing the general
properties of Hamiltonians, Hamiltonian structures etc, we also clarify the
origin of "exotic" charges in such models. We show that, in such models, there
exist at least two sets of non-local conserved charges (and more if $N>1$
supersymmetry is present) and that the "exotic" charges are part of this
non-local charge hierarchy. The construction of these non-local charges from
the Lax operator is explained.
