We present a phenomenological review of the decay K(L) --> pi-0-gamma-gamma, through the two dominant contributions of the pi-loop and vector meson dominance mechanisms. We have paid particular attention to consistency on the one hand between recent experimental measurements and theoretical models of K(L) --> pi-0-gamma-gamma decay and on the other hand between K(L) --> pi-0-gamma-gamma and other rather similar decays as K(S) --> gamma-gamma, K(L) --> gamma-gamma and eta --> pi-0-gamma-gamma.