4.2. Character encoding declaration
http://www.w3.org/TR/html-markup/syntax.html#character-encoding

"The value must be a valid character encoding name, and must be the preferred name for that encoding, as specified in the IANA [Character Sets] registry."

It would be good to have a link on 'preferred name' to make it clear that this includes the encoding name if there is no preferred name. See:

http://dev.w3.org/html5/spec/infrastructure.html#preferred-mime-name
"The preferred MIME name of a character encoding is the name or alias labeled as "preferred MIME name" in the IANA Character Sets registry, if there is one, or the encoding's name, if none of the aliases are so labeled." 

Otherwise it is misleading. (To be honest, it's still not overly clear. Much as new jargon is best avoided, this may be a case where we need a slightly different term, such as 'html-preferred'.)