Clarify event delivery behavior without active TX

Author: aahlenst

src/docs/antora/modules/ROOT/pages/events.adoc

@@ -195,6 +195,41 @@ class InventoryManagement {
 ----
 ======
 
+[CAUTION]
+====
+Spring Modulith writes events published without an ongoing transaction to the event publication log, but Spring Framework does not deliver them immediately. They will only be delivered when incomplete event publications are retried (see <<publication-registry>>). To receive the events immediately, annotate the event handler with `@TransactionalEventListener(fallbackExecution = true)`:
+
+[tabs]
+======
+Java::
++
+[source, java, role="primary"]
+----
+@Component
+class InventoryManagement {
+
+  @TransactionalEventListener(fallbackExecution = true)
+  @ApplicationModuleListener
+  void on(OrderCompleted event) { /* … */ }
+}
+----
+Kotlin::
++
+[source, kotlin, role="secondary"]
+----
+@Component
+class InventoryManagement {
+
+  @TransactionalEventListener(fallbackExecution = true)
+  @ApplicationModuleListener
+  fun on(event: OrderCompleted) { /* … */ }
+}
+----
+======
+
+Please see Spring Framework's documentation on https://docs.spring.io/spring-framework/reference/data-access/transaction/event.html#page-title[Transaction-bound Events] for further information.
+====
+
 [[publication-registry]]
 == The Event Publication Registry
 
@@ -204,6 +239,8 @@ On event publication, it finds out about the transactional event listeners that
 .The transactional event listener arrangement before execution
 image::event-publication-registry-start.png[]
 
+IMPORTANT: While Spring Framework continues to deliver events to handlers annotated with `@EventListener` alone, the event publication registry ignores them and does not write them to the event publication log. The event publication registry only considers methods annotated with `@TransactionalEventListener` or one of its subclasses, like `@ApplicationModuleListener`.
+
 Each transactional event listener is wrapped into an aspect that marks that log entry as completed if the execution of the listener succeeds.
 In case the listener fails, the log entry stays untouched so that retry mechanisms can be deployed depending on the application's needs.
 Automatic re-publication of the events can be enabled via the xref:appendix.adoc#configuration-properties[`spring.modulith.events.republish-outstanding-events-on-restart`] property.