[css-fonts] minor edits of font-variant subproperties

Author: John Daggett

css-fonts/Fonts.html

@@ -3845,17 +3845,22 @@ <h3 id=font-variant-position-prop><span class=secno>6.5 </span>Subscript
    given contiguous run of text, if a variant glyph is not available for all
    the characters in the run, simulated glyphs must be synthesized for all
    characters using reduced forms of the glyphs that would be used without
-   this feature applied. This is done to avoid a mixture of variant glyphs
-   and synthesized ones that would not align correctly.
-
-  <p>In the case of OpenType fonts that lack subscript or superscript glyphs
-   for a given character, user agents must use the appropriate subscript and
-   superscript metrics specified in the selected font's <a
+   this feature applied. This is done per run to avoid a mixture of variant
+   glyphs and synthesized ones that would not align correctly. In the case of
+   OpenType fonts that lack subscript or superscript glyphs for a given
+   character, user agents must use the appropriate subscript and superscript
+   metrics specified in the selected font's <a
    href="http://www.microsoft.com/typography/otspec/os2.htm#subxs">OS/2
    table</a> <a href="#OPENTYPE"
    rel=biblioentry>[OPENTYPE]<!--{{!OPENTYPE}}--></a> to calculate the size
    and offset of the synthesized substitutes.
 
+  <div class=figure><img alt="alternate superscripts vs. glyphs synthesized
+   using superscript metrics" src=superscript-alt-synth.png>
+   <p class=caption>Superscript alternate glyph (left), synthesized
+    superscript glyphs (middle), and incorrect mixture of the two (right)
+  </div>
+
   <p>In the past, user agents have used font-size and vertical-align to
    simulate subscripts and superscripts for the <a class=tag
    href="#sub">sub</a> and <span class=tag>sup</span> elements. To allow a
@@ -3867,21 +3872,15 @@ <h3 id=font-variant-position-prop><span class=secno>6.5 </span>Subscript
 
   <p>Authors should note that fonts typically only provide subscript and
    superscript glyphs for a subset of all characters supported by the font.
-   While subscript and superscript glyphs are often available for Latin
-   numbers, glyphs for punctuation and letter characters are less frequently
-   provided. The synthetic fallback rules defined for this property assure
-   that subscripts and superscripts will always appear but the appearance may
-   not match author expectations if the font used does not provide the
-   appropriate alternate glyph for all characters contained in a subscript or
-   superscript.
-
-  <div class=figure><img alt="alternate superscripts vs. glyphs synthesized
-   using superscript metrics" src=superscript-alt-synth.png>
-   <p class=caption>Superscript alternate glyph (left), synthesized
-    superscript glyphs (middle), and incorrect mixture of the two (right)
-  </div>
-
-  <p>This property is not cumulative, applying it to subelements within a
+   For example, while subscript and superscript glyphs are often available
+   for Latin numbers, glyphs for punctuation and letter characters are less
+   frequently provided. The synthetic fallback rules defined for this
+   property assure that subscripts and superscripts will always appear but
+   the appearance may not match author expectations if the font used does not
+   provide the appropriate alternate glyph for all characters contained in a
+   subscript or superscript.
+
+  <p>This property is not cumulative. Applying it to elements within a
    subscript or superscript won't nest the placement of a subscript or
    superscript glyph. Images contained within text runs where the value of
    this property is ‘<a href="#sub"><code class=property>sub</code></a>’
@@ -3892,8 +3891,14 @@ <h3 id=font-variant-position-prop><span class=secno>6.5 </span>Subscript
    would for the default glyphs, since this property does not affect the
    baseline position.
 
-  <p>Because of these limitations, font-variant-position is not recommended
-   for use in user agent stylesheets. Authors should use it in cases where
+  <p class=issue>Some have suggested that text decorations should apply to
+   the visual baseline of the variant glyphs, rather than the baseline
+   defined by the font.
+
+  <p>Because of these limitations, ‘<a
+   href="#propdef-font-variant-position"><code
+   class=property>font-variant-position</code></a>’ is not recommended for
+   use in user agent stylesheets. Authors should use it in cases where
    subscripts or superscripts will only contain the narrow range of
    characters supported by the fonts specified.
 
@@ -3914,7 +3919,7 @@ <h3 id=font-variant-position-prop><span class=secno>6.5 </span>Subscript
    <pre>@supports ( font-variant-position: sub ) {
 
   sub {
-    vertical-align: inherit;
+    vertical-align: baseline;
     font-size: 100%;
     line-height: inherit;
     font-variant-position: sub;
@@ -3991,7 +3996,10 @@ <h3 id=font-variant-caps-prop><span class=secno>6.6 </span>Capitalization:
      <td>no
   </table>
 
-  <p>Specifies control over capitalized forms.
+  <p>This property allows the selection of alternate glyphs used for small or
+   petite capitals or for titling. These glyphs are specifically designed to
+   blend well with the surrounding normal glyphs, to maintain the weight and
+   readability which suffers when text is simply resized to fit this purpose.
 
   <p>Individual values have the following meanings:
 
@@ -4041,11 +4049,6 @@ <h3 id=font-variant-caps-prop><span class=secno>6.6 </span>Capitalization:
     for this situation.
   </dl>
 
-  <p>This property allows the selection of alternate glyphs used for small or
-   petite capitals or for titling. These glyphs are specifically designed to
-   blend well with the surrounding normal glyphs, to maintain the weight and
-   readability which suffers when text is simply resized to fit this purpose.
-
   <p>The availability of these glyphs is based on whether a given feature is
    defined or not in the feature list of the font. User agents can optionally
    decide this on a per-script basis but should explicitly not decide this on
@@ -4105,7 +4108,7 @@ <h3 id=font-variant-caps-prop><span class=secno>6.6 </span>Capitalization:
    effect.
 
   <p>When casing transforms are used to simulate small capitals, the casing
-   transformations should match those used for the <span
+   transformations must match those used for the <span
    class=property>‘<code class=property>text-transform</code>’</span>
    property.