Mention that the program is only installed on supported platforms.

(Also add a paragraph break.)

I didn't specifically mention the platforms or what support is needed.
At least someone reading the manpage will have some idea why the tool
is missing from their system.

(Some manual pages mention this in the BUGS section, but I didn't do that.)

usr.sbin/apm/apm.8

@@ -1,4 +1,4 @@
-.\"	$NetBSD: apm.8,v 1.18 2008/04/30 13:11:01 martin Exp $
+.\"	$NetBSD: apm.8,v 1.19 2008/09/25 22:44:51 reed Exp $
 .\"
 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -51,6 +51,10 @@ communicates with the Advanced Power Management daemon,
 .Xr apmd 8 ,
 making requests of it for current power status or to place the system
 into a suspend or stand-by state.
+The
+.Nm
+tool is only installed on supported platforms.
+.Pp
 With no flags,
 .Nm
 displays the current power management state in verbose form.

usr.sbin/apmd/apmd.8

@@ -1,4 +1,4 @@
-.\"	$NetBSD: apmd.8,v 1.19 2008/04/30 13:11:01 martin Exp $
+.\"	$NetBSD: apmd.8,v 1.20 2008/09/25 22:44:51 reed Exp $
 .\"
 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -57,6 +57,10 @@ monitors the advanced power management (APM) pseudo-device, acting on
 signaled events and upon user requests as sent by the
 .Xr apm 8
 utility.
+The
+.Nm
+daemon is only installed on supported platforms.
+.Pp
 For suspend and standby request events delivered by the BIOS, or via
 .Xr apm 8 ,
 .Nm

usr.sbin/bad144/bad144.8

@@ -26,7 +26,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)bad144.8	8.1 (Berkeley) 6/6/93
-.\"	$NetBSD: bad144.8,v 1.15 2003/08/07 11:25:12 agc Exp $
+.\"	$NetBSD: bad144.8,v 1.16 2008/09/25 22:44:51 reed Exp $
 .\"
 .Dd June 6, 1993
 .Dt BAD144 8
@@ -55,6 +55,9 @@
 .Nm
 can be used to inspect the information stored on a disk that is used by
 the disk drivers to implement bad sector forwarding.
+The
+.Nm
+tool is only installed on supported platforms.
 .Pp
 Available options:
 .Pp

usr.sbin/eeprom/eeprom.8

@@ -1,4 +1,4 @@
-.\"	$NetBSD: eeprom.8,v 1.14 2008/04/30 13:11:02 martin Exp $
+.\"	$NetBSD: eeprom.8,v 1.15 2008/09/25 22:44:51 reed Exp $
 .\"
 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -60,6 +60,10 @@
 .Nm
 provides an interface for displaying and changing the contents of the
 EEPROM or openprom.
+The
+.Nm
+tool is only installed on supported platforms.
+.Pp
 Without any arguments,
 .Nm
 will list all of the known fields and their corresponding values.

usr.sbin/ofctl/ofctl.8

@@ -1,4 +1,4 @@
-.\"	$NetBSD: ofctl.8,v 1.3 2008/04/30 13:11:02 martin Exp $
+.\"	$NetBSD: ofctl.8,v 1.4 2008/09/25 22:44:51 reed Exp $
 .\"
 .\" Copyright (c) 2006 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -42,6 +42,10 @@
 .Nm
 provides an interface for displaying the OpenPROM or OpenFirmware
 device tree and node properties.
+The
+.Nm
+program is only installed on supported platforms.
+.Pp
 Without any arguments,
 .Nm
 will dump the full tree.