There are other methods of encoding bit streams that force regular transitions in voltage level, such as Manchester encoding. In Manchester, there is always a transition in the center of the bit time. If the data bit is a 0, then transition is from high to low voltage, while 1 is from low to high voltage. Fig. 23.2.5 shows the Manchester encoding of 01001110. There is also a differential Manchester, like NRZI, where the polarity can be differential Manchester reversed without destroying the bit stream.