As an interesting side note, ham radio operators heavily use a digital mode called PSK31. It stands for "Phase Shift Keying, 31 Baud". As I understand it, the

As an interesting side note, ham radio operators heavily use a digital mode called PSK31. It stands for "Phase Shift Keying, 31 Baud". As I understand it, the 31 bit/s transmission rate was chosen because it is close to the entropy that operators can generate by typing on their keyboards. PSK31 does not transmit 8 bit bytes, but instead uses what they call a Varicode, a kind of Fibonacci code. More frequent characters are encoded using fewer bits, thus the encoded bit rate is an approximation of the entropy in the text stream.