[en] The light neutral colour-singlet spin-zero bosons P⁰ and P³ expected in contemporary extended technicolour theories have some small induced flavour-changing couplings, even in monophagic theories where their couplings are mainly flavour diagonal. Their non-observation in K⁺ decay meaons that msub(p)0,3 approx. > 350 MeV, leading one to expect direct quark-lepton transitions mediating K⁰sub(L) → μe decay close to the present experimental upper limit. In the absence of some as yet unknown suppression mechanisms, either P⁰ and P³ should be observed in bottom decays with a branching ratio approaching 100% (which may already be experimentally excluded) and/or they should be observed in charm decays with branching ratios approx. > 1% and/or the decay K⁰sub(L) → μe should be detected within an order of magnitude of the present upper limit. (orig.)