Fix syntax

Author: xiaochengh

css-anchor-1/Overview.bs

@@ -417,7 +417,7 @@ Taking Scroll Into Account: the 'anchor-scroll' property {#scroll}
 
 <pre class=propdef>
 Name: anchor-scroll
-Value: none | <<dashed-ident>>
+Value: none | implicit | <<dashed-ident>>
 Initial: none
 Inherited: no
 Applies to: [=absolutely-positioned=] elements
@@ -646,8 +646,8 @@ Default Anchors: the 'anchor-default' property</h3>
 
 <pre class=propdef>
 Name: anchor-default
-Value: <<anchor-element>>
-Initial: implicit
+Value: none | <<dashed-ident>>
+Initial: none
 Applies to: [=absolutely positioned=] elements
 Inherited: no
 Animation type: discrete
@@ -659,6 +659,17 @@ allowing multiple elements to use the same set of [=anchor functions=]
 (and [=position fallback lists=]!)
 while changing which [=anchor element=] each is referring to.
 
+Values are defined as follows:
+
+<dl dfn-type=value dfn-for=anchor-default>
+	: <dfn>none</dfn>
+	:: The property has no effect.
+
+	: <dfn><<dashed-ident>></dfn>
+	:: This <<dashed-ident> is the [=default anchor specifier=] for all
+	   [=anchor functions=] on the element.
+</dl>
+
 Its values are identical to the <<anchor-element>> term in ''anchor()'' and ''anchor-size()''.
 
 <div class=example>