Specifies digital test signals suitable for evaluating the low-frequency response of equipment handling serial digital video signals as defined by SMPTE 259M-1993. These test signals are fully valid digital component video as defined in ANSI/SMPTE 125M-1995. They are also useful digital composite video signals suitable for testing serial equipment in an out-of-service mode. Although a range of signals will produce the desired low-frequency effects, two specific signals are defined to test cable equalization and phase locked loop (PLL) lock-in, respectively.