  The decays $K_{L,S} \to 3 \gamma $ are not forbidden by any selection rules
or symmetry principles. However, gauge invariance and Bose statistics dictate
that every photon pair in these transitions has at least two units of angular
momentum. This gives rise to an extraordinary suppression. Using a simple
model, we obtain the branching ratios $B(K_L \to 3 \gamma) \sim 3 \cdot
10^{-19}$, $B(K_S \to 3 \gamma) \sim 5 \cdot 10^{-22} $.
