—This review article explores the notion of radio flexibility, its various versions (as presented in a brief taxonomy) and its efficient instantiations under various metrics, primary among which is the broad applicability of a parametrically compact, single model or design over a large set of modes and scenarios. The focus is on the algorithmic part of the base-band. It is argued that this systematic approach to the subject yields benefits both in understanding past results as well as charting new research frontiers.