[css-fonts-4] Clarify font-weight language

#629

Author: litherum

css-fonts-4/Overview.bs

@@ -157,8 +157,7 @@ at least as dark as its predecessor. Only values between 1 - 999 are valid, and
 
 	<div class="figure"><img alt="weight mappings for a family with 300, 600 weights" src="hiraginoweights.png" /><p class="caption">Weight mappings for a font family with 300 and 600 weight faces</p></div>
 
-	Most user agents model a font has having a particular weight which often
-	corresponds to the list <a href="#font-weight-numeric-values">above</a>.
+	Most user agents model a font as having a particular weight which often corresponds to one of the numbers in the nine-step scale mentioned <a href="#font-weight-numeric-values">above</a>.
 	While this is true of most fonts, some fonts may be configurable so as to
 	support a range of weights. In this situation, the user agent uses a face
 	with a weight as close as possible to the weight requested (see the