[css3-values] feedback

Sugestion:
It's good put the definition of *em unity* and other units on all documents
of W3C as:
http://www.w3.org/TR/css3-values/#em-unit http://www.w3.org/TR/css3-values/
http://www.w3.org/TR/css3-mediaqueries/  because the conception of the
units is important. It's so confusing using another sites like Adobe
Glossary and Wikipedia.

Example from Adobe glossary:

em, em space, em quad
A common unit of measurement in typography. Em is traditionally defined as
the width of the uppercase M in the current face and point size. It is more
properly defined as simply the current point size. For example, in 12-point
type, em is a distance of 12 points.
http://www.adobe.com/uk/type/topics/glossary.html

Wikipedia http://en.wikipedia.org/wiki/Em_%28typography%29

Example from a W3C site. But think this site is outdated
The meaning of "em" has changed over the years. Not all fonts have the
letter "M" in them (for example Chinese), but all fonts have a height. The
term has therefore come to mean the height of the font - not the width of
the letter "M".
http://www.w3.org/WAI/GL/css2em.htm

Thanks.