  We investigate refinement in the context of choreographies. We introduce
refinable global choreographies allowing for the underspecification of
protocols, whose interactions can be refined into actual protocols. Arbitrary
refinements may spoil well-formedness, that is the sufficient conditions that
guarantee a protocol to be implementable. We introduce a typing discipline that
enforces well-formedness of typed choreographies. Then we unveil the relation
among refinable choregraphies and their admissible refinements in terms of an
axiom scheme.
