--- etc/rc.initdiskless	2012-03-13 10:17:09.000000000 +0100
+++ etc/rc.initdiskless	2012-03-13 10:17:09.000000000 +0100
@@ -39,7 +39,10 @@ 
 # for which memory filesystems will be created and filled,
 # and T is one of the "template" directories below:
 #
-#  base		universal base, typically a replica of the original root;
+#  base.${rel}	universal base for the given major release, typically a 
+#		replica of the original root;
+#  base		universal base, typically a replica of the original root,
+#		effective only if base.${rel} does not exist;
 #  default	secondary universal base, typically overriding some
 #		of the files in the original root;
 #  ${ipba}	where ${ipba} is the assigned broadcast IP address
@@ -53,7 +56,9 @@ 
 #  ip/${ip}	same as above
 #
 # Template directories are scanned in the order they are listed above,
-# with each successive directory overriding (merged into) the previous one;
+# with each successive directory overriding (merged into) the previous one
+# (except in the case of the base directory, where the release-specific
+# base is chosen if exists to help multiple major releases to work together);
 # non-existing directories are ignored.  The subdirectory forms exist to
 # help keep the top level /conf manageable in large installations.
 #
@@ -261,7 +266,7 @@ 
 done
 
 # The list of directories with template files
-templates="base default"
+templates="default"
 if [ -n "${bootp_ipbca}" ]; then
 	templates="${templates} ${bootp_ipbca} bcast/${bootp_ipbca}"
 fi
@@ -275,7 +280,17 @@ 
 # If /conf/diskless_remount exists, remount all of /conf.
 handle_remount /conf
 
-# Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
+# Extract the major revision from uname
+rel=`expr \`uname -r\` : '\(.\)'`
+# If we have a "base.${rel}" directory, use that as base, otherwise fall back
+# to "base"
+if [ -d "/conf/base.${rel}" ]; then
+	templates="base.${rel} ${templates}"
+else
+	templates="base ${templates}"
+fi
+
+# Resolve templates in /conf/base[.${rel}], /conf/default, /conf/${bootp_ipbca},
 # and /conf/${bootp_ipa}.  For each subdirectory found within these
 # directories:
 #
--- share/man/man8/diskless.8	2011-08-08 15:13:22.000000000 +0200
+++ share/man/man8/diskless.8	2012-03-13 10:14:56.000000000 +0100
@@ -255,6 +255,7 @@ 
 .Pp
 The scripts provide four
 overriding directories situated in
+.Pa /conf/base.<major-release> or
 .Pa /conf/base ,
 .Pa /conf/default ,
 .Pa /conf/<broadcast-ip> ,
@@ -267,6 +268,14 @@ 
 on the
 .Nm
 machine.
+If you run different major releases, you should maintain a base /etc for
+each one to provide backwards compatibility for older releases.
+You can do this by installing major release specific /etc into
+.Pa /conf/base.<major-release>
+The
+.Nm
+boot script will first look for this release specific base, then
+the standard base in this order. The more specific base will be used.
 You can clone the server's
 .Pa /etc
 here or you can create a special file which tells the