We classify all possible SU(2) × U(1) gauge models with three triplet quarks according to the representations of the quarks, requiring the validity of the Cabibbo theory and absence of strangeness changing neutral processes in lowest order. Then we investigate in detail the questions of lepton-hadron universality, ΔS ≠ 0 neutral processes in higher orders, and strong interactions. Characteristic differences between the various types of models show up. Further we give the predictions for the ratios R and R of neutral to charged ν and ν cross sections below color threshold. Only a rather small region of the R- R plane is accessible by the totality of all the models. The experimental points lie within this region, and more precise measurements could well discriminate between the various types of models.