diff --git a/sys/man/8/plan9.ini b/sys/man/8/plan9.ini
index cf01a45ac..96ff418fd 100644
--- a/sys/man/8/plan9.ini
+++ b/sys/man/8/plan9.ini
@@ -867,6 +867,18 @@ The main feature of the interface is the ability to watch
 battery life (see
 .IR stats (8)).
 It is not on by default because it causes problems on some laptops.
+.SS USB
+.SS \fL*nousbprobe=\fP
+Disable USB host controller detection.
+.SS \fL*nousbohci=\fP
+.SS \fL*nousbuhci=\fP
+.SS \fL*nousbehci=\fP
+.SS \fL*nousbxhci=\fP
+Disable specific USB host controller types.
+.SS \fLnousbrc=\fP
+Disable
+.IR nusbrc (8)
+startup at boot time.
 .SS \fLnousbhname=\fP
 When defined,
 .IR nusbrc (8)