[en] We review recent advances in the understanding of rare decays of particles in the (s,d,u) sector, with emphasis on the radiative decays of Kaons and Hyperons. From among the K-decays we concentrate on K_L^o→γ1⁺1^-, K_L^o→μ⁺μ^-, K_L^o→π^oe⁺e^- and K⁺→π⁺1⁺1^-, each of these having some particularly characteristic feature. After a general overview of radiative hyperon decays, we discuss the transitions Ω^-→ Ξ ^-γ and Ξ ^-→ Σ^-γ which are singled out for their potential in the verification of the flavour-changing s→dγ transition of the Standard Model. (author)