I consider non standard EW couplings of light right-handed quarks to W and Z
suggested in a systematic non decoupling bottom-up low-energy effective theory
approach to possible extensions of the Standard Model. New experimental tests
in K^L_{mu3} decays based on recent measurements and scalar form factor
analysis are discussed. A successful NLO fit to the standard set of Z-pole and
other NC data is presented as well.Comment: 9 pages, 2 figures. Talk given at the KAON07 International
Conference, May 21-25 2007, Frascati, Ital
