diff --git a/selectors-4/Overview.bs b/selectors-4/Overview.bs
index bab506d87a5..339df55d7d7 100644
--- a/selectors-4/Overview.bs
+++ b/selectors-4/Overview.bs
@@ -812,8 +812,6 @@ Pseudo-classing Pseudo-elements
unless otherwise-specified, none of these pseudo-classes
will match on the pseudo-element.
- Issue: Clarify that '':not()'' and '':is()'' can be used when containing above-mentioned pseudos.
-
For example, since the '':hover'' pseudo-class specifies
that it can apply to any pseudo-element,
@@ -831,8 +829,14 @@ Pseudo-classing Pseudo-elements
whereas ''::first-line:hover'' only matches if the first line itself is hovered.
+ The [=logical combination pseudo-classes=]
+ '':not()'', '':is()'', and '':where()''
+ are also valid immediately following a [=pseudo-element=]
+ provided their arguments all adhere to the above restriction.
+
Note: Note that, unless otherwise specified in a future specification,
pseudo-classes other than the user action pseudo-classes
+ (and logical combination pseudo-classes restricted to them)
are not valid when compounded to a pseudo-element;
so, for example, ''::before:first-child'' is an invalid selector.
@@ -988,6 +992,22 @@ Invalid Selectors and Error Handling
Logical Combinations
+ Selector logic can be manipulated by
+ [=compound selector|compounding=] (logical AND),
+ [=selector lists=] (logical OR),
+ and the logical combination pseudo-classes
+ '':is()'', '':where()'', and '':not()''.
+ The [=logical combination pseudo-classes=]
+ are allowed anywhere that any other [=pseudo-classes=] are allowed,
+ but pass any restrictions to their arguments.
+ (For example, if only [=compound selectors=] are allowed,
+ then only [=compound selectors=] are valid within an '':is()''.)
+
+ Note: Since inside '':is()'' and '':where()''
+ invalid arguments are dropped without invaliding the [=pseudo-class=] itself,
+ selector arguments that are invalidated by contextual restrictions
+ likewise do not invalidate the '':is()'' pseudo-class itself.
+
Selector Lists