Add a precision requirement for numbers.

--HG--
extra : rebase_source : 9fff8aeff8eb65a859937e50b5e6021bcb1c8f1b

Author: tabatkins

css3-values/Overview.html

@@ -761,6 +761,9 @@ <h2 id=numeric-types><span class=secno>4. </span> Numeric Data Types</h2>
    UAs's supported range, it must also be clamped to the closest supported
    value.
 
+  <p> UAs must support at least 3 digits of precision after the decimal point
+   in numeric values.
+
   <h3 id=integers><span class=secno>4.1. </span> Integers: the &lsquo;<a
    href="#integer-value"><code class=css>&lt;integer&gt;</code></a>&rsquo;
    type</h3>

css3-values/Overview.src.html

@@ -428,6 +428,9 @@ <h2 id="numeric-types">
 		if the result is outside the UAs's supported range,
 		it must also be clamped to the closest supported value.
 
+	<p>
+		UAs must support at least 3 digits of precision after the decimal point in numeric values.
+
 <h3 id="integers">
 Integers: the ''&lt;integer&gt;'' type</h3>