diff --git a/index.html b/index.html
index cce9947..f9deccf 100644
--- a/index.html
+++ b/index.html
@@ -234,7 +234,8 @@
Differences for an EditContext editing hostEditContext editing host becomes editable,
unless that node has a [^html-global/contenteditable^] attribute set to "false".
-
The user agent handles focus and caret navigation for any editable element in the EditContext editing host.
+ The user agent handles focus and caret navigation for any editable element in the EditContext editing host (except when the
+ [=associated element=] is a [=canvas=]; see below in this section).
The EditContext editing host receives key events and the beforeinput
event as specified in [[uievents]].
@@ -257,6 +258,28 @@ Differences for an EditContext editing hostEditContext editing host as a direct result of user action
event as specified in [[uievents]].
+
+ When the {{Document}} being edited has an [=active EditContext=], the user agent must not fire
+ composition events against the
+ EditContext editing host as a direct result of user action. Instead they will be fired against the {{EditContext}} as part
+ of [=update the EditContext|updating the EditContext=] or [=deactivate an EditContext|deactivating the EditContext=].
+
+
+
+ When the [=active EditContext=]'s [=associated element=] is a [=canvas=], there are further differences:
+
+
+ -
+ The user agent is unable to handle caret navigation and selection since it doesn't have information
+ about how text is laid out in the [=canvas=], so the author has to implement caret navigation and selection.
+
+ -
+ The user agent is unable to present inline spelling and grammar suggestions since it doesn't have information
+ about how the text is laid out in the [=canvas=], so if the author wants to support spelling and grammar suggestions,
+ they have to implement that themselves.
+
+
+