http://www.freebsd.org/cgi/query-pr.cgi?pr=usb/107924

It doesnt apply on 7.0-BETA2 as no usbd.8

*** 6.2-RELEASE/src/usr.sbin/usbd/usbd.8	Sun Jan 14 20:48:31 2007
--- new-generic/src/usr.sbin/usbd/usbd.8	Sun Jan 14 20:52:06 2007
***************
*** 130,138 ****
--- 130,141 ----
  .It Pa /dev/usb1
  .It etc .
  .El
+ .Sh BUGS
+ Detach does not work. Use Devd if you need to call a script on detach.
  .Sh SEE ALSO
  .Xr usb 4 ,
  .Xr usbd.conf 5
+ .Xr devd 8
  .Sh HISTORY
  The
  .Nm