UTF-8 is variable width using 8, 16, 24, or 32 bits per code point. I wondered why you didn't write that "UTF-8 is variable width using 8, 16, 24, 32, 40, or 4

UTF-8 is variable width using 8, 16, 24, or 32 bits per code point. I wondered why you didn't write that "UTF-8 is variable width using 8, 16, 24, 32, 40, or 48 bits per code point", because that's how Prosser/Thompson/Pike's UTF-8 idea was proposed, as shown in the "most elegant hack" article. And here's the answer from Wikipedia: In November 2003 UTF-8 was restricted by RFC 3629 to end at U+10FFFF, in order to match the constraints of the UTF-16 character encoding. This removed all 5- and 6-byte sequences, and about half of the 4-byte sequences. Even though they eliminated the 5th and 6th bytes, UTF-8 can still represent all of Unicode's 1,114,112 code points. I'm mentioning this because others probably are wondering the same thing.