[css2] Issue 149.

bert-github · bert-github · commit 1e969d87c644 · 2010-10-28T18:26:37.000Z
--HG--
extra : convert_revision : svn%3A73dc7c4b-06e6-40f3-b4f7-9ed1dbc14bfc/trunk%403079
diff --git a/css2/changes.src b/css2/changes.src
@@ -1,6 +1,6 @@
 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
 <html lang="en">
-<!-- $Id: changes.src,v 2.128 2010-10-26 19:48:54 bbos Exp $ -->
+<!-- $Id: changes.src,v 2.129 2010-10-28 18:26:37 bbos Exp $ -->
 <HEAD>
 <TITLE>Changes</TITLE>
 </HEAD>
@@ -4352,6 +4352,26 @@ used in the 'font-size' property, refers to the <em>parent
 element's</em> 'ex' (just as 'em' refers to the parent's 'em' in that
 case.)
 
+<!--========================== issue 149 ==========================-->
+
+<h3 id="t.4.3.2a"><a
+href="/TR/2009/CR-CSS2-20090908/syndata.html#length-units">
+Section&nbsp;4.3.2 Lengths</a></h3>
+
+<p><span class=date>[2010-10-28]</span> A UA must now <em>either</em>
+display absolute lengths (cm, in, pt, etc.) at their real size
+<em>or</em> make px align with device pixel boundaries near the 0.0213
+degrees viewing angle, but not both. In either case, 3px must equal
+4pt.
+
+<p>(Until now, authors could use absolute lengths for physical sizes
+and px for aligning to device pixels, but couldn't know the number of
+pt in a px, except in combination with Media Queries. Authors can no
+longer choose between absolute or device-related units, but can use px
+and pt interchangeably. This should only affect relatively
+low-resolution devices: above 300 dots per inch, the maximum error is
+about 16%.)
+
 <!--========================== issue 152 ==========================-->
 
 <h3 id="t.4.3.4a"><a
