Thus, we observe that, in one stroke, the [*usual*]{} superfield formalism (USF) produces the CF-type condition(s) as well as the proper quantum gauge \[i.e., (anti-)BRST\] symmetries for a quantum gauge theory. It is, therefore, clear that the USF sheds light on various aspects of quantum gauge theories when they are discussed within the framework of BRST formalism.

The USF \[4-10\], however, leads to the derivation of nilpotent (anti-)BRST symmetry transformations [*only*]{} for the gauge field and associated (anti-)ghost fields of a given [*quantum*]{} gauge theory. It does not shed any light on the derivation of the (anti-)BRST symmetry transformations, associated with the [*matter*]{} fields, in a given [*interacting*]{} quantum gauge theory where there is a coupling between the gauge field and matter fields. In a set of papers \[11-15\], the above superfield formalism has been [*consistently*]{} extended so as to derive precisely the (anti-)BRST symmetry transfromations for the gauge, matter and (anti-)ghost fields [*together*]{}. Whereas the [*usual*]{} superfield formalism exploits the theoretical potential and power of the horizontality condition (HC), its extended version utilizes the theoretical strength of the HC as well as the gauge invariant restrictions (GIRs) [*together*]{} in a consistent manner. The extended version of the USF has 