This Recommendation contains parameters and definitions relating to adaptive chromatic dispersion compensators necessary for the transmission and detection of optical signals in a system producing dynamic variations in chromatic dispersion. The adaptive dispersion compensators described concern both single-channel and multi-channel applications. This Recommendation defines the specifications and fundamental parameters of adaptive dispersion compensators (ADC). This Recommendation distinguishes between adaptive dispersion compensators and adaptive dispersion compensator transmitters and receivers which can incorporate both forms of electrical and optical compensation for chromatic dispersion.