diff --git a/css-ui-4/Overview.bs b/css-ui-4/Overview.bs
index 91aa823aab0..a0a448c7699 100644
--- a/css-ui-4/Overview.bs
+++ b/css-ui-4/Overview.bs
@@ -1541,6 +1541,11 @@ except:
where the computed value is always ''user-select/contain''
regardless of the specified value
+
+ on locked editable elements
+ where the computed value is ''user-select/contain''
+ if the specified value was ''user-select/text'' or ''user-select/auto''
+
when the specified value is ''user-select/auto'',
which computes one of the other values as defined below
@@ -1551,6 +1556,10 @@ an editable element is either
an editing host
or a mutable form control with textual content,
such as <{textarea}>.
+A locked editable element is
+a normally mutable form control with textual content,
+when it is placed in a non mutable state,
+such as a <{textarea}> with the readonly attribute.
Issue: Should there be constraints
on what happens to the computed value
@@ -1570,7 +1579,7 @@ or maybe all values should compute to ''user-select/text''.
the computed value is ''user-select/none''
- If the element is an editable element,
+ If the element is an editable element or a locked editable element,
the computed value is ''user-select/contain''