diff --git a/selectors-4/Overview.bs b/selectors-4/Overview.bs
index ca9992ad56b..bc0aa68f726 100644
--- a/selectors-4/Overview.bs
+++ b/selectors-4/Overview.bs
@@ -2632,6 +2632,23 @@ Collapse State: the '':open'' pseudo-class
Note: A ":closed" pseudo-class might be added in the future
once the full set of things that support '':open'' is known.
+
+Popover State: the '':popover-open'' pseudo-class
+
+ The :popover-open pseudo-class represents an element
+ that has both “popover-showing” and “popover-hidden” states
+ and which is currently in the “popover-showing” state.
+
+ Note: This is distinct from '':open'' because
+ an element can have element-specific open and closed states
+ and also have separate popover-showing and popover-hidden states
+ associated with being a popover.
+
+ Exactly what “popover-showing” and “popover-hidden” states
+ mean is host-language specific,
+ but is exemplified by the presence of the HTML <{html-global/popover}> attribute
+ and the associated popover visibility state.
+
Modal (Exclusive Interaction) State: the '':modal'' pseudo-class
@@ -4192,8 +4209,11 @@ Changes since the 7 May 2022 Working Draft
Significant changes since the 7 May 2022 Working Draft:
* Marked '':blank'' as at-risk and removed the at-risk status from '':read-write'' and '':has()''
- * Added '':open'' and '':closed'' pseudo-classes.
- (Issue 7319)
+ * Added '':open'' pseudo-class.
+ (Issue 7319,
+ Issue 11039)
+ * Added '':popover-open'' pseudo-class.
+ (Issue 8637)
* Disallowed [=pseudo-elements=] from '':has()'' unless explicitly allowed
by the pseudo-element’s definition.
(Issue 7463)