Release notes for multiarch features

release_notes/ocp-4-18-release-notes.adoc

@@ -552,6 +552,27 @@ With this release, the Agent-based Installer supports creating assets that can b
 
 For more information, see xref:../installing/installing_with_agent_based_installer/installing-using-iscsi.adoc#installing-using-iscsi[Preparing installation assets for iSCSI booting].
 
+[id="ocp-4.18-postinstallation-configuration_{context}"]
+=== Postinstallation configuration
+
+[id="ocp-4.18-migrate-x86-cp-to-arm-arch_{context}"]
+==== Migrating the x86 control plane to arm64 architecture on {aws-full}
+
+With this release, you can migrate the control plane in your cluster from `x86` to `arm64` architecture on {aws-first}. For more information, see xref:../updating/updating_a_cluster/migrating-to-multi-payload.adoc#migrating-from-x86-to-arm64-cp_updating-clusters-overview[Migrating the x86 control plane to arm64 architecture on Amazon Web Services].
+
+[id="ocp-4.18-support-for-config-image-stream-import-beh_{context}"]
+==== Support for configuring the image stream import mode behavior (Technology Preview)
+
+This feature provides a new field `imageStreamImportMode` in the `image.config.openshift.io/cluster` resource. The `imageStreamImportMode` field controls the import mode behavior of image streams. You can set the `imageStreamImportMode` field to either of the following values:
+
+* `Legacy`
+* `PreserveOriginal`
+
+You must enable the `TechPreviewNoUpgrade` feature set in the `FeatureGate` custom resource (CR) to enable the `imageStreamImportMode` feature. For more information, see "Understanding feature gates".
+
+For more information, see [Image controller configuration parameters].
+//xref will be added post merging the PR for the imageStreamImportMode` doc.
+
 [id="ocp-release-notes-olm_{context}"]
 === Operator lifecycle
 
@@ -1659,6 +1680,11 @@ In the following tables, features are marked with the following statuses:
 |General Availability
 |General Availability
 
+|Support for configuring the image stream import mode behavior
+|Not Available
+|Not Available
+|Technology Preview
+
 |====
 
 [discrete]