CMPWG Sep-3-2015:

The OptionSet description is very, very confusing:
The "Value" parameter says:
"Array of bytes representing the bits in the option set. The length of the ByteString depends on the number of bits."

There's no explanation of the relationship between bits and bytes. Is there one byte per bit?

It was realized later that the intent is to PREVENT bitmasks being anything other than 8-bit blocks, which makes sense.

I would like to propose modifying the description to make this clearer, for example:

Value: "Array of bytes representing the bits in the option set, thus requiring bitmasks to be in blocks of 8-bits. The length of the ByteString depends on the number of bits. For example, a 10-bit bitmask would equate to 2-bytes, with the remaining 6-bits being ignored."

Hopefully this clarification will also make the "validBits" parameter make sense too.