[css-fonts-3] edits to fix w3c#2796

Author: svgeesus

css-fonts-3/Fonts.src.html

@@ -169,24 +169,7 @@ <h2 class="no-num no-toc" id=status>Status of this document</h2>
 
 <h3 class="no-num no-toc" id="atrisk">Features at risk</h3>
 
-<p>The following features are at risk; if interoperable
-implementations are not found, they may be removed to advance the other
-features in this specification to Proposed Recommendation:</p>
-
-<ul>
-<li>fallback handling for text decoration in superscript/subscript variant glyphs ('font-variant-position')</li>
-<li>The <em>font specific</em> functions accepted by 'font-variant-alternates' and 'font-variant'. This includes the entire <code>@font-feature-values</code> at-rule, as well as the following functions:
-<ul>
-<li><a href="#stylistic">stylistic()</a></li>
-<li><a href="#styleset">styleset()</a></li>
-<li><a href="#character-variant">character-variant()</a></li>
-<li><a href="#swash">swash()</a></li>
-<li><a href="#ornaments">ornaments()</a></li>
-<li><a href="#annotation">annotation()</a></li>
-</ul>
-</li>
-<li>Synthesis of the 'font-variant-position' property</li>
-</ul>
+<!-- at-risk features removed in prepartion for Proposed Recommendation-->
 
 <nav id="toc">
 <h2 class="no-num no-toc" id="contents">Table of contents</h2>
@@ -3030,19 +3013,23 @@ <h3 id="font-variant-position-prop">Subscript and superscript forms: the <a href
 <p>Because of the semantic nature of subscripts and superscripts, when
 the value is either 'sub' or 'super' for a 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
+the run, simulated glyphs <!-- must --> should be synthesized for all characters using
 reduced forms of the glyphs that would be used without 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 synthesize appropriate subscript and superscript
+user agents <!-- must --> should synthesize appropriate subscript and superscript
 glyphs.</p>
 
 <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)</p></div>
 
+<!--
+  at-risk must downgraded to should
+  see https://github.com/w3c/csswg-drafts/issues/2796#issuecomment-398565265
+-->
 <p>In situations where text decorations are only applied to runs
 of text containing superscript or subscript glyphs, the synthesized
-glyphs must be used to avoid problems with the placement of decorations.</p>
+glyphs <!-- must --> should be used, to avoid problems with the placement of decorations.</p>
 
 <p>In the past, user agents have used font-size and
 vertical-align to simulate subscripts and superscripts for the