diff --git a/admin_manual/configuration_server/config_sample_php_parameters.rst b/admin_manual/configuration_server/config_sample_php_parameters.rst
index fa842ffd9..6387e3b79 100644
--- a/admin_manual/configuration_server/config_sample_php_parameters.rst
+++ b/admin_manual/configuration_server/config_sample_php_parameters.rst
@@ -683,7 +683,7 @@ Available values:
     automatically, delete other files anytime if space needed
 * ``D1, D2``
     keep files and folders in the trash bin for at least D1 days and
-    delete when exceeds D2 days
+    delete when exceeds D2 days (note: files will not be deleted automatically if space is needed)
 * ``disabled``
     trash bin auto clean disabled, files and folders will be kept forever