diff --git a/src/reference/docbook/file.xml b/src/reference/docbook/file.xml
index 1a388847a1..b1f2c46897 100644
--- a/src/reference/docbook/file.xml
+++ b/src/reference/docbook/file.xml
@@ -431,6 +431,10 @@
If the target file exists, the message payload is silently
ignored.
+
+ When using a temporary file suffix (default: .writing), the IGNORE
+ mode will apply if the final file name exists, or the temporary file name exists.
+