The document says that the encoding is 11 bits for two characters, which means that Base45 plus that encoding is very efficient, since 45^2 / 2^11 = 0.988, so o

The document says that the encoding is 11 bits for two characters, which means that Base45 plus that encoding is very efficient, since 45^2 / 2^11 = 0.988, so only 1.2% of the capacity is wasted.