diff --git a/config/config.sample.php b/config/config.sample.php
index 04d75ea7e8..8901c041c6 100644
--- a/config/config.sample.php
+++ b/config/config.sample.php
@@ -566,7 +566,7 @@ $CONFIG = array(
  *     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
  *