  The most severe constraints on quark-lepton four-fermion contact interactions
come from the agreement of atomic parity violation measurements with the
Standard Model. In this letter I note that for contact interactions which arise
in theories of composite quarks and leptons, other approximate global
symmetries than parity can eliminate the contribution of contact terms to
atomic parity violation. The most stringent tests of compositeness therefore
come from the high energy collider experiments at LEP II, HERA, and the
Tevatron.
