In discussing the intensities of emission lines, the Einstein A is an appropriate parameter to use, whereas in discussing the equivalent widths of absorption lines the appropriate parameter is osc...In discussing the intensities of emission lines, the Einstein A is an appropriate parameter to use, whereas in discussing the equivalent widths of absorption lines the appropriate parameter is oscillator strength f. In this respect it differs from oscillator strength or Einstein coefficient, in which the oscillator strength or Einstein coefficient of a line is equal to the average oscillator strength of Einstein coefficient of its components.