More edits to OCP 3.3 release notes

Author: adellape

install_config/upgrading/manual_upgrades.adoc

@@ -660,6 +660,15 @@ have previously deployed a
 xref:../../admin_guide/high_availability.adoc#configuring-a-highly-available-routing-service[highly-available
 routing service].
 
+ifdef::openshift-enterprise[]
+[NOTE]
+====
+If you previously customized your HAProxy routing template, then, depending on
+the changes, additional steps may be required due to changes in the routing data
+structure starting in {product-title} 3.3. See xref:../../release_notes/ocp_3_3_release_notes.adoc#ocp-33-routing-data-structure-changes[Routing Data Structure Changes] in the {product-title} 3.3 Release Notes for details.
+====
+endif::[]
+
 ifdef::openshift-origin[]
 [IMPORTANT]
 ====