diff --git a/performance.rst b/performance.rst
index 0e980a2550d..1d786972988 100644
--- a/performance.rst
+++ b/performance.rst
@@ -327,6 +327,15 @@ Sections are a way to split the profile timeline into groups. Example::
     $this->stopwatch->start('processing-file');
     $this->stopwatch->stopSection('parsing');
 
+All events that don't belong to any named section are added to the special section
+``__root__``. This way you can get all stopwatch events, even if you don't know
+their names::
+
+    foreach($this->stopwatch->getSectionEvents('__root__') as $event) {
+        echo (string) $event;
+    }
+
+
 Learn more
 ----------