Add note that event listeners' event name is optional since version 5.5

diff --git a/docs/package/pip/event-listener.md b/docs/package/pip/event-listener.md
index de2da7f5f400f89abb888a7e5885e5d3518860b7..cd471a8357fa29b6f26b7a1c6ec593a923b53cef 100644 (file)
--- a/docs/package/pip/event-listener.md
+++ b/docs/package/pip/event-listener.md
@@ -18,6 +18,8 @@ The event class name is the name of the class in which the event is fired.
 The event name is the name given when the event is fired to identify different events within the same class.
 You can either give a single event name or a comma-separated list of event names in which case the event listener listens to all of the listed events.
 
+!!! info "Since the introduction of [the new event system with version 5.5](../../migration/wsc54/php.md#events), the event name is optional and defaults to `:default`."
+
 ### `<listenerclassname>`
 
 The listener class name is the name of the class which is triggered if the relevant event is fired.