  The present report of the RF2 Topical Group to Snowmass 2021 describes the
physics case for the studies of weak decays of strange and light quarks.
Ongoing and proposed precision measurements of kaon, hyperon, pion and
$\eta^{(\prime)}$ meson decays allow for unique tests of the Standard Model
(SM). This includes precision measurements of the elements of the CKM
quark-mixing matrix leading to stringent unitarity tests; precision symmetry
tests including lepton flavor and lepton number conservation; and precision
lepton flavor universality tests. In the context of models beyond the SM
description, strange and light quark decay experiments provide sensitivity to
new physics up to the PeV mass scale, as well as leading sensitivities to
scenarios involving feebly interacting hidden sectors below the GeV mass scale.
