In this review we first discuss the theoretical motivations for possible CPT
violation and deviations from ordinary quantum-mechanical behavior of
field-theoretic systems in the context of an extended class of quantum-gravity
models. Then we proceed to a description of precision tests of CPT symmetry
using mainly neutral kaons. We emphasize the possibly unique role of neutral
meson factories in providing specific tests of models where the
quantum-mechanical CPT operator is not well-defined, leading to modifications
of Einstein-Podolsky-Rosen particle correlators. Finally, we present tests of
CPT, T, and CP using charged kaons, and in particular K_l4 decays, which are
interesting due to the high statistics attainable in experiments.Comment: Invited contribution to DAFNE Physics Handbook, 23 pages LaTeX, 9 eps
figures incorporate
