  We limit ourselves basically to the SU(2) flavor sector of the CKM matrix, as
probed in processes like nuclear $\beta$-decay, normal and radiative muon
capture and neutrino reactions. Current interests in this primarily stem from
our aspirations to interpret the weak form factors of the nucleon in the
framework of QCD. Given a standard set of known form factors, we can look also
in these processes for possible physics signals beyond the standard model.
