[css-pseudo-4][editorial] Clarify note, fix markup

Author: fantasai

css-pseudo-4/Overview.bs

@@ -437,18 +437,21 @@ First Letters and Associated Punctuation</h4>
   </ul>
 
   <div class="note">
-    Informally represented, the [=first-letter text=]’s pattern here
+    Informally, the [=first-letter text=]’s pattern here
     can be roughly
-    (ignoring the exclusion of word separators from <code>Zs</code>)
-    represented as
+    (ignoring the exclusions from <code>Zs</code>)
+    represented as the regular expression
     <code highlight="bnf" style="font-family: inherit">
-    (P (Zs|P)*)? (L\|N\|S) ((Zs|P−(Ps|Pd))* (P−(Ps|Pd))?</code>
+    (P (Zs|P)*)? (L&#x7c;N|S) ((Zs|P−(Ps|Pd))* (P−(Ps|Pd))?</code>--
     or, alternatively,
     <code highlight="bnf" style="font-family: inherit">
-    (&#91;P] [Zs P]*)? [L N S] ([Zs [P--[Ps Pd]]]* [P--[Ps Pd]])?</code>
+    (&#91;P] [Zs P]*)? [L N S] ([Zs [P--[Ps Pd]]]* [P--[Ps Pd]])?</code>--
+    where the Unicode category abbreviation represents the set
+    of all [=typographic character units=] belonging to that category.
+
     <!-- this is not actually BNF, but it highlights better that way -->
 
-   <!-- Bikeshed is <a href="https://github.com/tabatkins/bikeshed/issues/2202">eating punctuation</a> in this note (unless escaped with undocumented escape sequences), which is not helpful. -->
+    <!-- Bikeshed is <a href="https://github.com/tabatkins/bikeshed/issues/2202">eating punctuation</a> in this note (unless escaped with undocumented escape sequences), which is not helpful. -->
 
     <pre class=railroad>
       Optional:
@@ -815,45 +818,6 @@ Selecting Highlighted Content: the ''::selection'', ''::search-text'', ''::targe
       identified by the given [=custom highlight name=].
       The <<custom-ident>> argument is required.
       See [[CSS-HIGHLIGHT-API-1]] for details.
-      <wpt>
-      css/css-highlight-api/painting/custom-highlight-painting-001.html
-      css/css-highlight-api/painting/custom-highlight-painting-002.html
-      css/css-highlight-api/painting/custom-highlight-painting-003.html
-      css/css-highlight-api/painting/custom-highlight-painting-004.html
-      css/css-highlight-api/painting/custom-highlight-painting-005.html
-      css/css-highlight-api/painting/custom-highlight-painting-006.html
-      css/css-highlight-api/painting/custom-highlight-painting-007.html
-      css/css-highlight-api/painting/custom-highlight-painting-008.html
-      css/css-highlight-api/painting/custom-highlight-painting-009.html
-      css/css-highlight-api/painting/custom-highlight-painting-010.html
-      css/css-highlight-api/painting/custom-highlight-painting-011.html
-      css/css-highlight-api/painting/custom-highlight-painting-012.html
-      css/css-highlight-api/painting/custom-highlight-painting-013.html
-      css/css-highlight-api/painting/custom-highlight-painting-014.html
-      css/css-highlight-api/painting/custom-highlight-painting-015.html
-      css/css-highlight-api/painting/custom-highlight-painting-iframe-001.html
-      css/css-highlight-api/painting/custom-highlight-painting-iframe-002.html
-      css/css-highlight-api/painting/custom-highlight-painting-iframe-003.html
-      css/css-highlight-api/painting/custom-highlight-painting-iframe-004.html
-      css/css-highlight-api/painting/custom-highlight-painting-iframe-005.html
-      css/css-highlight-api/painting/custom-highlight-painting-iframe-006.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-001.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-002.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-003.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-004.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-005.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-006.html
-      css/css-highlight-api/painting/custom-highlight-painting-invalidation-007.html
-      css/css-highlight-api/painting/custom-highlight-painting-prioritization-001.html
-      css/css-highlight-api/painting/custom-highlight-painting-prioritization-002.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-001.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-002.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-003.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-004.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-005.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-006.html
-      css/css-highlight-api/painting/custom-highlight-painting-staticrange-007.html
-      </wpt>
   </dl>
 
   The <a>highlight pseudo-elements</a>
@@ -934,7 +898,7 @@ Styling Highlights</h3>
 
   <ul>
     <li>'forced-color-adjust' (used in [=forced colors mode=] to resolve colors)
-      and 'color-scheme' (used to resolve [=system colors=])
+      and 'color-scheme' (used to resolve <<system-color>> values)
     <li>'font-size', 'font-family', etc. (used to resolve ''em'' and other [=font-relative lengths=]).
     <li>'line-height' (used to resolve ''lh'' units)
     <li>[=custom properties=] [[!CSS-VARIABLES-1]] (used in ''var()'' substitutions)