I wonder if OP used "octets" because physical pattern in the CD used to represent a byte is a sequence of 17 pits and lands.

BTW, byte size during the history varied from 4 to 24 bit! Even now, based on interpretation, you can say 16 bit bytes do exist.

Char type can be 16 bit on some DSP systems.

I was curious, so I checked. Before this comment, I only knew about 7 bit bytes.