[en] Hybrid calculations are reported for elastic electron scattering from the highly polar molecule CsCl, which establish the origin of the shoulder at 30⁰ recently observed in the differential cross section at 20 eV. The hybrid method used incorporates dynamic effects of both dipole scattering at intermediate and long range (important at small angles theta), and core scattering (important, typically, for larger angles). The shoulder, in spite of its location at small theta, is demonstrated conclusively to be a core effect. (author)