so something like this... ok mandoc@
Index: sbin/isakmpd/isakmpd.conf.5
===================================================================
RCS file: /cvs/src/sbin/isakmpd/isakmpd.conf.5,v
retrieving revision 1.127
diff -u -p -r1.127 isakmpd.conf.5
--- sbin/isakmpd/isakmpd.conf.5 22 Sep 2010 13:45:16 -0000 1.127
+++ sbin/isakmpd/isakmpd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -53,14 +53,13 @@ Inside a section many tag/value pairs ca
.Bd -unfilled
.Ar Tag Ns = Ns Ar Value
.Ed
-If the value needs more space than fits on a single line, it's possible to
-continue it on the next by ending the first with a backslash character
-immediately before the newline character.
-This method can extend a value for an arbitrary number of lines.
-.Pp
-Comments can be put anywhere in the file by using a hash mark
-.Pq Sq \&# .
-The comment extends to the end of the current line.
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
+Comments can be put anywhere in the file using a hash mark
+.Pq Sq # ,
+and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
.Pp
Often the right-hand side values consist of other section names.
This results in a tree structure.
Index: share/man/man5/pf.conf.5
===================================================================
RCS file: /cvs/src/share/man/man5/pf.conf.5,v
retrieving revision 1.494
diff -u -p -r1.494 pf.conf.5
--- share/man/man5/pf.conf.5 20 May 2011 22:57:20 -0000 1.494
+++ share/man/man5/pf.conf.5 15 Jun 2011 11:27:51 -0000
@@ -62,9 +62,14 @@ A method for detecting a host's operatin
Some example rulesets.
.El
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
+.Pp
Additional configuration files can be included with the
.Ic include
keyword, for example:
Index: usr.sbin/bgpd/bgpd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/bgpd.conf.5,v
retrieving revision 1.114
diff -u -p -r1.114 bgpd.conf.5
--- usr.sbin/bgpd/bgpd.conf.5 30 Apr 2011 07:52:33 -0000 1.114
+++ usr.sbin/bgpd/bgpd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -56,9 +56,13 @@ the sections should be grouped and appea
.Nm
in the order shown above.
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
.Pp
Additional configuration files can be included with the
.Ic include
Index: usr.sbin/hostapd/hostapd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/hostapd/hostapd.conf.5,v
retrieving revision 1.37
diff -u -p -r1.37 hostapd.conf.5
--- usr.sbin/hostapd/hostapd.conf.5 16 Apr 2009 20:13:13 -0000 1.37
+++ usr.sbin/hostapd/hostapd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -47,9 +47,13 @@ The concepts and details about the optio
.Xr hostapd 8 .
.El
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
.Pp
Additional configuration files can be included with the
.Ic include
Index: usr.sbin/ldapd/ldapd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/ldapd/ldapd.conf.5,v
retrieving revision 1.13
diff -u -p -r1.13 ldapd.conf.5
--- usr.sbin/ldapd/ldapd.conf.5 28 Jan 2011 09:26:22 -0000 1.13
+++ usr.sbin/ldapd/ldapd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -28,9 +28,14 @@
is the configuration file for the LDAP daemon
.Xr ldapd 8 .
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
-.Pq # ,
+.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
+.Pp
Arguments containing whitespace should be surrounded by double quotes
.Pq \&" .
.Pp
Index: usr.sbin/relayd/relayd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/relayd/relayd.conf.5,v
retrieving revision 1.122
diff -u -p -r1.122 relayd.conf.5
--- usr.sbin/relayd/relayd.conf.5 23 May 2011 10:44:59 -0000 1.122
+++ usr.sbin/relayd/relayd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -78,9 +78,13 @@ see
.Xr services 5
for details.
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
.Pp
Additional configuration files can be included with the
.Ic include
Index: usr.sbin/sasyncd/sasyncd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/sasyncd/sasyncd.conf.5,v
retrieving revision 1.17
diff -u -p -r1.17 sasyncd.conf.5
--- usr.sbin/sasyncd/sasyncd.conf.5 30 Jun 2010 00:44:36 -0000 1.17
+++ usr.sbin/sasyncd/sasyncd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -39,9 +39,13 @@ is the configuration file for the
.Xr sasyncd 8
daemon.
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
-and extends to the end of the current line.
+and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
.Pp
Since the file contains the shared secret key used to encrypt data
between this host and the others,
Index: usr.sbin/smtpd/smtpd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/smtpd/smtpd.conf.5,v
retrieving revision 1.42
diff -u -p -r1.42 smtpd.conf.5
--- usr.sbin/smtpd/smtpd.conf.5 9 Jun 2011 17:41:52 -0000 1.42
+++ usr.sbin/smtpd/smtpd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -27,9 +27,14 @@
is the configuration file for the mail daemon
.Xr smtpd 8 .
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
-.Pq # ,
+.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
+.Pp
Arguments containing whitespace should be surrounded by double quotes
.Pq \&" .
.Pp
Index: usr.sbin/snmpd/snmpd.conf.5
===================================================================
RCS file: /cvs/src/usr.sbin/snmpd/snmpd.conf.5,v
retrieving revision 1.15
diff -u -p -r1.15 snmpd.conf.5
--- usr.sbin/snmpd/snmpd.conf.5 21 Apr 2011 17:31:12 -0000 1.15
+++ usr.sbin/snmpd/snmpd.conf.5 15 Jun 2011 11:27:51 -0000
@@ -40,9 +40,13 @@ Global runtime settings for
Custom configuration of SNMP object identifiers and values.
.El
.Pp
+The current line can be extended over multiple lines using a backslash
+.Pq Sq \e .
Comments can be put anywhere in the file using a hash mark
.Pq Sq # ,
and extend to the end of the current line.
+Take care when commenting out text which is part of a multi-line block:
+the comment is effective until the end of the entire block.
.Pp
Additional configuration files can be included with the
.Ic include
