Data strobe is a coding method in which the data signal and the strobe signal together form the coded signal.
In D/S coding, the signal state is determined by an XOR operation of both signals. Either the level of the D/S signal is changed by the data signal or the strobe, but not simultaneously by both.
This means that if both signals have a change of state, the state of the D/S signal does not change. D/S coding reduces bit skew and realizes simple clock recovery. D/S coding is used in IEEE 1394, known as FireWire, among others.