In telecommunication, the term black facsimile transmission has the following meanings: 1. * In facsimile systems using amplitude modulation, that form of transmission in which the maximum transmitted power corresponds to the maximum density of the subject. 2. * In facsimile systems using frequency modulation, that form of transmission in which the lowest transmitted frequency corresponds to the maximum density of the subject. Source: from Federal Standard 1037C and from MIL-STD-188