diff --git a/docs/eventing/experimental-features.md b/docs/eventing/experimental-features.md
index 9d42911d516..150a72e84e3 100644
--- a/docs/eventing/experimental-features.md
+++ b/docs/eventing/experimental-features.md
@@ -51,4 +51,33 @@ data:
 
 ## Features list
 
-<!-- TODO there are no experimental features at the moment -->
+### `KReference.Group` field
+
+**Flag name**: `kreference-group`
+
+**Stage**: Alpha, disabled by default
+
+**Tracking issue**: https://github.com/knative/eventing/issues/5086
+
+When using the `KReference` type to refer to another Knative resource, you can just specify the API `group` of the resource, instead of the full `APIVersion`.
+
+For example, in order to refer to an `InMemoryChannel`, instead of the following spec:
+
+```yaml
+apiVersion: messaging.knative.dev/v1
+kind: InMemoryChannel
+name: my-channel
+```
+
+You can use the following:
+
+```yaml
+group: messaging.knative.dev
+kind: InMemoryChannel
+name: my-channel
+```
+
+With this feature you can allow Knative to resolve the full `APIVersion` and further upgrades, deprecations and removals of the referred CRD without affecting existing resources.
+
+!!! note
+    At the moment this feature is implemented only for `Subscription.Spec.Subscriber.Ref`.