  The standard oracle operator corresponding to a function f is a unitary
operator that computes this function coherently, i.e. it maintains
superpositions. This operator acts on a bipartite system, where the subsystems
are the input and output registers. In distributed quantum computation, these
subsystems may be spatially separated, in which case we will be interested in
its classical and entangling capacities. For an arbitrary function f, we show
that the unidirectional classical and entangling capacities of this operator
are log_{2}(n_{f}) bits/ebits, where n_{f} is the number of different values
this function can take. An optimal procedure for bidirectional classical
communication with a standard oracle operator corresponding to a permutation on
Z_{M} is given. The bidirectional classical capacity of such an operator is
found to be 2log_{2}(M) bits. The proofs of these capacities are facilitated by
an optimal distributed protocol for the implementation of an arbitrary standard
oracle operator.
