Recent progress related to the modeling of various pressure-induced absorption bands of binary molecular systems, involving dissimilar and like pairs of molecules such as H2, He, N2, CH4, etc., is reported. The notes include references to the existing efforts based on quantum line shape computations that reproduce the laboratory measurements of pressure-induced absorption closely. The results may be considered a most reliable data base permitting an evaluation of pressure-induced absorption as function of frequency, temperature, and gas density for various binary molecular systems and spectral bands in the infrared region of the spectrum. ¿ American Geophysical Union 1991