We propose a generalization to the 'self-consistent' approach, which represents the acid-base component of the work of adhesion between two condensed media as a sum of cross products of acid and base components of the media in contact. Two important particular cases are considered in detail: (a) the theory of 'acid and base components of the surface free energy', and (b) our new 'asymmetrical approach' in which dimensions of acid-base parameters for liquids and solids are different, and the enthalpy of adhesion between a liquid and a solid is expressed in terms of Gutmann's acceptor and donor numbers of the liquid and surface densities of the acid and base sites on the solid surface. It is shown that characterization of a solid surface using two complementary techniques, inverse gas chromatography and contact angle measurement, makes possible the calculation of the number of acid-base bonds at the interface and the estimation of their energy. All discussions are illustrated by our contact angle data, obtained by wetting four different solid surfaces (polymer coatings on glass plates) by six low-molecular-weight liquids. For untreated glass and three coatings, the important energy parameters of the surface (the total surface free energy and its three components, and surface densities of acid and base sites) are determined. Possibilities for the application of a multiliquid self-consistent approach, in which acid and base parameters of all solid surfaces and liquids can be determined simultaneously, is discussed.