[selectors4] :where() has 0 specificity

The functional pseudo-class like :matches() with 0 specificity
is named :where().
w3c#2143 (comment)

resolves w3c#2143

selectors-4/Overview.bs

@@ -139,7 +139,7 @@ Selectors Overview</h2>
 				<td>[[#matches]]
 				<td>4
 			<tr>
-				<td><code>E:something(<var>s1</var>, <var>s2</var>, &hellip;)</code>
+				<td><code>E:where(<var>s1</var>, <var>s2</var>, &hellip;)</code>
 				<td>an E element that matches <a>compound selector</a> <var>s1</var>
 						and/or <a>compound selector</a> <var>s2</var> but contributes no specificity.
 				<td>[[#zero-matches]]
@@ -1199,20 +1199,18 @@ The Negation Pseudo-class: '':not()''</h3>
 
 
 <h3 id="zero-matches">
-The Specificity-adjustment Pseudo-class: '':something()''</h3>
+The Specificity-adjustment Pseudo-class: '':where()''</h3>
 
-	The Specificity-adjustment pseudo-class, <dfn id="something-pseudo">:something()</dfn>,
+	The Specificity-adjustment pseudo-class, <dfn id="where-pseudo">:where()</dfn>,
 	is a functional pseudo-class
 	with the same syntax and functionality as '':matches()''.
-	Unlike '':matches()'', neither the '':something'' pseudo-class, nor any of its arguments
+	Unlike '':matches()'', neither the '':where'' pseudo-class, nor any of its arguments
 	contribute to the specificity of the selector--
 	its specificity is always zero.
 
 	This is useful for introducing filters in a selector
 	while keeping the associated style declarations easy to override.
 
-	ISSUE: This pseudo-class needs a name. See <a href="https://github.com/w3c/csswg-drafts/issues/1170">previous discussion</a>, <a href="https://github.com/w3c/csswg-drafts/issues/2143">open issue</a>.
-
 	<div class="example">
 		Below is a common example where the specificity heuristic fails
 		to match author expectations:
@@ -1228,10 +1226,10 @@ The Specificity-adjustment Pseudo-class: '':something()''</h3>
 			}
 		</pre>
 
-		However, by using '':something()'' the author can explicitly declare their intent:
+		However, by using '':where()'' the author can explicitly declare their intent:
 
 		<pre>
-			a:something(:not(:hover)) {
+			a:where(:not(:hover)) {
 				text-decoration: none;
 			}
 
@@ -3332,7 +3330,7 @@ Calculating a selector's specificity</h2>
 			The specificity of a '':not()'' pseudo-class is replaced by
 			the specificity of the most specific complex selector in its selector list argument.
 		<li>
-			The specificity of a '':something()'' pseudo-class is replaced by zero.
+			The specificity of a '':where()'' pseudo-class is replaced by zero.
 	</ul>
 
 	<div class="example">
@@ -3343,7 +3341,7 @@ Calculating a selector's specificity</h2>
 				a specificity of (0,0,1)--like a tag selector--when matched against <code>&lt;em></code>,
 				and a specificity of (1,0,0)--like an ID selector--when matched against  <code>&lt;em id=foo></code>.
 			<li>
-				''div:something(em, #foo#bar#baz)'' has
+				''div:where(em, #foo#bar#baz)'' has
 				a specificity of (0,0,1): only the ''div'' contributes to selector specificity.
 			<li>
 				'':nth-child(even of li, .item)'' has