osdocs13571 Adding warning message about mismatched service UIDs

Author: Daniel Chadwick

Diff for: modules/customize-certificates-understanding-service-serving.adoc

@@ -32,3 +32,9 @@ $ for I in $(oc get ns -o jsonpath='{range .items[*]} {.metadata.name}{"\n"} {en
       done
 ----
 ====
+
+
+[WARNING]
+====
+After you create the service, if you re-create the service, the secret will no longer have a matching service UID. A mismatched service UID will lead to an automatic certificate renewal failure.
+====