Leading Questions in an Extended Standard Model

We would like to discuss the language to write an extended Standard Model - using renormalizable quantum field theory as the framework; to start with certain basic units together with a certain gauge group. Specifically we use the left-handed and right-handed spinors to form the basic units together with SUc(3) x SUL(2) x U(1) x SUf(3) as the gauge group. We could write down the extended Standard Model, though the details of the Higgs mechanism remains to be worked out. The same general quest appeared about forty years ago - the so-called "How to build up a model". It is timely to address the same question again especially since we could now put together "Dirac similarity principle" and "Higgs minimum hypothesis" as two additional working rules.