Earlier quoted context omitted.
CSS is just an embarrassment of mistakes: white-space: nowrap So they take a word "whitespace" which needs no hyphen and jam one in. Then they take two completely distinct words "no wrap" and jam them together with no separator. And then you have to remember both of these on the same rule .
"White space" is two words, not one.
- The XML W3C Rec: https://www.w3.org/TR/xml/
- The HTTP 1.0 RFC: https://tools.ietf.org/html/rfc1945
However, there are exception. The Unicode character database has a property called "White_Space" which implies it is two words: http://www.unicode.org/reports/tr44/#White_Space