[css-pseudo-4] Clarify that the marker of a list-item ::before/::after pseudo-element can be selected, but not with '::marker' because that expands to '*::marker' and * doesn't match pseudos. w3c#3826 w3c#3766

Author: fantasai

css-lists-3/Overview.bs

@@ -90,7 +90,7 @@ Declaring a List Item</h2>
 Markers</h2>
 
 	The defining feature of the <a>list item</a> <a>display type</a>
-	is its <dfn lt="marker | marker box">marker</dfn>,
+	is its <dfn lt="marker | marker box" export>marker</dfn>,
 	a symbol or ordinal that helps denote the beginning of each <a>list item</a> in a list.
 	In the CSS layout model,
 	<a>list item</a> <a>markers</a> are represented by

css-pseudo-4/Overview.bs

@@ -45,7 +45,7 @@ spec:fill-stroke-3; type:property; text:stroke-width
   and how they can be styled.
   For more information on pseudo-elements in general,
   and on their syntax and interaction with other <a>selectors</a>,
-  see [[!SELECTORS4]].
+  see [[!SELECTORS-4]].
 
 <h2 id="typographic-pseudos">
 Typographic Pseudo-elements</h2>
@@ -731,8 +731,8 @@ Generated Content Pseudo-elements: ''::before'' and ''::after''</h3>
 List Markers: the ''::marker'' pseudo-element</h3>
 
   The <dfn>::marker</dfn> pseudo-element represents
-  the automatically generated marker box of a list item.
-  (See ''display: list-item''.)
+  the automatically generated [=marker box=] of a [=list item=].
+  (See [[CSS-DISPLAY-3]] and [[CSS-LISTS-3]].)
 
   The following CSS properties apply to a ''::marker'' pseudo-element:
   <ul>
@@ -755,6 +755,15 @@ List Markers: the ''::marker'' pseudo-element</h3>
     }
   </pre>
 
+  Note: Although the ''::marker'' pseudo-element can represent
+  the [=marker box=] of a ''::before'' or ''::after'' pseudo-element,
+  the [=compound selector=] ''::marker'',
+  which expands to ''*::marker'' [[SELECTORS-4]],
+  will not select these markers--
+  an [=originating element=] that is a [=pseudo-element=]
+  needs to be explicitly specified in the [=selector=],
+  e.g. ''::before::marker''.
+
 <h3 id="placeholder-pseudo">
 Placeholder Input: the ''::placeholder'' pseudo-element</h3>