It does say 1 letter languages not 1 character languages. But then if they were included, there'd be a comment on how C# is two letters, a discussion whether #

It does say 1 letter languages not 1 character languages. But then if they were included, there'd be a comment on how C# is two letters, a discussion whether # should be counted as a letter or not, which really is one of these "look, we're arguing axioms now" discussions.