diff --git a/share/man/man4/devctl.4 b/share/man/man4/devctl.4
index dc035f1246d2..4403cb4fdd71 100644
--- a/share/man/man4/devctl.4
+++ b/share/man/man4/devctl.4
@@ -23,12 +23,16 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 26, 2014
+.Dd September 21, 2020
 .Dt DEVCTL 4
 .Os
 .Sh NAME
 .Nm devctl
 .Nd "device event reporting and device control interface"
+.Sh SYNOPSIS
+The
+.Nm
+driver is automatically included in the kernel.
 .Sh DESCRIPTION
 The
 .Nm
@@ -124,5 +128,17 @@ driver.
 The attach message driver has already claimed this device.
 One cannot use the detach messages to flush data to the device.
 The device is already gone.
+.Pp
+All values passed back are of the form
+.Sq key=value
+or
+.Sq key="value" .
+When the latter, the string
+.Dq value
+must have any internal backslashes doubled.
+It must also have any internal double quote characters
+.Sq "
+preceded by a backslash.
+All other characters should be passed through.
 .Sh SEE ALSO
 .Xr devd 8