  We review the basic properties of the currCFL-K^0 phase in dense quark
matter. At asymptotically large densities, three-flavor quark matter is in the
color-flavor locked (CFL) state. The currCFL-K^0 state is a way to respond to
``stress'' on the quark Cooper pairing, imposed at more moderate densities by
the strange quark mass and the conditions of electric and color neutrality. We
show how a kaon supercurrent is incorporated in a purely fermionic formalism,
and show that the net current vanishes due to cancellation of fermion and
charge-conjugate fermion contributions.
