--- src/share/man/man4/snp.4	2006/02/17 19:37:09	1.3
+++ src/share/man/man4/snp.4	2007/08/04 03:32:49	1.4
@@ -17,33 +17,39 @@
 .Ft int
 .Fn ioctl fd FIONREAD &result
 .Sh DESCRIPTION
-/dev/snp? are snoop devices which allow users to attach to any tty
+.Pa /dev/snp?
+are snoop devices which allow users to attach to any tty
 and watch activities on it.
 The kernel must be compiled with
 .Cd "device snp" ,
 or the
 .Nm
-device must be loaded,
-for these devices to be available.
+module must be loaded, for these devices to be available.
 .Pp
 To associate a given
 .Nm
 device with a tty to be observed, open the
 .Nm
-device and then use the SNPSTTY ioctl.
+device and then use the
+.Dv SNPSTTY
+ioctl.
 The argument passed to the ioctl is the address of a variable of type
-dev_t.
-To detach the snp device from a tty use a pointer to a value of (dev_t)-1.
+.Vt dev_t .
+To detach the snp device from a tty use a pointer to a value of
+.Vt ( dev_t ) Ns Li -1 .
 .Pp
-The SNPGTTY ioctl returns information about the current tty attached to
-the open
+The
+.Dv SNPGTTY
+ioctl returns information about the current tty attached to the open
 .Nm
 device.
 .Pp
-The FIONREAD ioctl returns a positive value equal to the number of characters
+The
+.Dv FIONREAD
+ioctl returns a positive value equal to the number of characters
 in a read buffer.
 Special values defined are:
-.Bl -tag -width SNP_TTYCLOSE
+.Bl -tag -width ".Dv SNP_TTYCLOSE"
 .It Dv SNP_OFLOW
 device overflow occurred, device detached.
 .It Dv SNP_TTYCLOSE