[css3-values] Defining "whitespace"

Hi,

css3-values mentions whitespace characters in a few places, but does not 
define the concept. It should reference one of these:

http://www.w3.org/TR/CSS21/syndata.html#whitespace
http://dev.w3.org/csswg/css3-syntax/#whitespace


(By the way, normalizing on "whitespace" vs. "white space" would be nice.)

Cheers,
-- 
Simon Sapin