  It has long been known that nonstrange baryon-meson scattering in the 1/N_c
expansion of QCD greatly simplifies when expressed in terms of t-channel
exchanges: The leading-order amplitudes satisfy the selection rule I_t = J_t.
We show that I_t = J_t, as well as Y_t = 0, also hold for the leading
amplitudes when the baryon and/or meson contain strange quarks, and also
characterize their 1/N_c corrections, thus opening a new front in the
phenomenological study of baryon-meson scattering and baryon resonances.
