diff --git a/doc/source/admin/interfaces/boot.rst b/doc/source/admin/interfaces/boot.rst
index cd9420cc9b..b9f0bda3e2 100644
--- a/doc/source/admin/interfaces/boot.rst
+++ b/doc/source/admin/interfaces/boot.rst
@@ -76,6 +76,11 @@ appended to the kernel command line::
 
     nofb nomodeset vga=normal console=ttyS0,115200n8
 
+.. note::
+   Ironic does not do any de-duplication of the resulting kernel parameters.
+   Both kernel itself and dracut seem to give priority to the last instance
+   of the same parameter.
+
 Common options
 --------------