Since the equations defining Y'CbCr are formed in a way that rotates the entire nominal RGB color cube and scales it to fit within a (larger) YCbCr color cube, there are some points within the Y'CbCr color cube that "cannot" be represented in the corresponding RGB domain (at least not within the nominal RGB range). This causes some difficulty in determining how to correctly interpret and display some Y'CbCr signals. These out-of-range Y'CbCr values are used by xvYCC to encode colors outside the BT.709 gamut.