diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index b53779702371..9d7413059bd1 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -445,6 +445,15 @@ options 	DEBUG_MEMGUARD
 #
 options 	DEBUG_REDZONE
 
+#
+# EARLY_PRINTF enables support for calling a special printf (eprintf)
+# very early in the kernel (before cn_init() has been called).  This
+# should only be used for debugging purposes early in boot.  Normally,
+# it is not defined.  It is commented out here because this feature
+# isn't generally available. And the required eputc() isn't defined.
+#
+#options	EARLY_PRINTF
+
 #
 # KTRACE enables the system-call tracing facility ktrace(2).  To be more
 # SMP-friendly, KTRACE uses a worker thread to process most trace events