diff --git a/setup.sh b/setup.sh
index 1d9fc4e..57cd7ae 100644
--- a/setup.sh
+++ b/setup.sh
@@ -796,7 +796,11 @@ EOF
     fi
 
 # Up here maybe 'ro quiet' instead of 'ro'. This is ZFSBootMenu's kernel
-# command line.
+# command line. In MBR/Syslinux/extlinux mode /it/ must pass arguments to
+# ZFSBootMenu's kernel so check /boot/syslinux/syslinux.cfg for how we start
+# ZFSBootMenu in this mode. The .Kernel.CommandLine in
+# /etc/zfsbootmenu/config.yaml is irrelevant for us in MBR/Syslinux/extlinux
+# mode.
 
     # Assign cmdline for final kernel start. This is our Arch Linx kernel
     # command line.