[css-writing-modes] Clarify handling of iframe

Author: fantasai

css-writing-modes/Overview.bs

@@ -819,10 +819,12 @@ Block Flow Direction: the 'writing-mode' property</h3>
     The 'text-orientation' property then determines how text is laid out within the line box.
 
   <p>The content of replaced elements do not rotate due to the writing mode:
-    images, for example, remain upright. However replaced content
-    involving text (such as MathML content or form elements) should match
-    the replaced element's writing mode and line orientation if the UA
-    supports such a vertical writing mode for the replaced content.
+    images and external content such as from <code>&lt;iframe></code>s, for example, remain upright,
+    and the <a>default object size</a> of 300px&times;150px does not re-orient.
+    However embedded replaced content involving text
+    (such as MathML content or form elements)
+    should match the replaced element's writing mode and line orientation
+    if the UA supports such a vertical writing mode for the replaced content.
 
   <div class="example">
     <p>In the following example, two block elements (1 and 3) separated
@@ -2660,6 +2662,7 @@ Full-width Characters</h5>
     <li>Removed ''sideways-left'' and ''sideways-right'' value of 'text-orientation',
         redefined ''sideways'' to behave as ''sideways-right'',
         and added ''sideways-lr'' and ''sideways-rl'' values to 'writing-mode' for usage with non-vertical writing systems.
+        (See <a href="http://www.w3.org/mid/55982414.1080905@inkedblade.net">discussion</a>.)
     <li>Removed ''use-glyph-orientation'' value of 'text-orientation' and defined 'glyph-orientation-vertical' as an alias of 'text-orientation'
       consistent with how CSS aliases are handled (see 'page-break-inside' for an example).
     <li>

css-writing-modes/issues-cr-2014.bs-issues

@@ -386,15 +386,24 @@ Comment:  http://lists.w3.org/Archives/Public/www-style/2015Jul/0405.html
 Response: http://lists.w3.org/Archives/Public/www-style/2015Aug/0290.html
 Closed:   Accepted
 Open:     =SVGWG= Review wording.
+
 ----
-Issue 48.
-Summary:  Behavior of <iframe> in vertical writing mode: 2 clarifications
+Issue 48a.
+Summary:  Orientation of 300x150 default object size in vertical writing modes
 From:     Jonathan Kew
 Comment:  http://lists.w3.org/Archives/Public/www-style/2015Aug/0049.html
 Response: http://lists.w3.org/Archives/Public/www-style/2015Aug/0061.html
-Open:     Accepted
+Closed:   Accepted
 Resolved: http://www.w3.org/mid/CADhPm3s66T2JeNNJb59J5pbGy0+DSC7QMibPn8gTJ5j+i65T-A@mail.gmail.com
 ----
+Issue 48b.
+Summary:  Clarify application of writing-mode to external content
+From:     Jonathan Kew
+Comment:  http://lists.w3.org/Archives/Public/www-style/2015Aug/0049.html
+Response: =INSERT HERE=
+Open:     Accepted
+Resolved: Editor's discretion
+----
 Issue 49.
 Summary:  proposed 'writing-mode:sideways-*' values: effect on computed value of 'display'
 From:     Jonathan Kew