man: updates to sysctl.d(5)

diff --git a/man/sysctl.d.xml b/man/sysctl.d.xml
index 9c108b0b7c3030af1a0efe82cf455db868a77a5f..20f2e24820e53e2d38225a5e5593c526a1a12dc4 100644 (file)
--- a/man/sysctl.d.xml
+++ b/man/sysctl.d.xml
@@ -54,38 +54,51 @@
         <refsect1>
                 <title>Description</title>
 
-               <para><command>systemd</command> uses configuration files
-               from the above directories to configure
+               <para><command>systemd</command> uses configuration
+               files from the above directories to configure
                <citerefentry><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
-               kernel parameters to load during boot.</para>
+               kernel parameters during boot.</para>
         </refsect1>
 
         <refsect1>
                <title>Configuration Format</title>
 
-               <para>The configuration files should simply contain a
-               list of variable assignments, separated by
-               newlines. Empty lines and lines whose first
-               non-whitespace character is # or ; are ignored.</para>
-
-                <para>Note that both / and . are accepted as
-                separators in sysctl variable names.</para>
-
-                <para>Each configuration file is named in the style of
-                <filename>&lt;program&gt;.conf</filename>.
-                Files in <filename>/etc/</filename> overwrite
-                files with the same name in <filename>/usr/lib/</filename>.
-                Files in <filename>/run</filename> overwrite files with
-                the same name in <filename>/etc/</filename> and
-                <filename>/usr/lib/</filename>. Packages should install their
-                configuration files in <filename>/usr/lib/</filename>, files
-                in <filename>/etc/</filename> are reserved for the local
-                administration, which possibly decides to overwrite the
-                configurations installed from packages. All files are sorted
-                by filename in alphabetical order, regardless in which of the
-                directories they reside, to ensure that a specific
-                configuration file takes precedence over another file with
-                an alphabetically later name.</para>
+               <para>The configuration files contain a list of
+               variable assignments, separated by newlines. Empty
+               lines and lines whose first non-whitespace character
+               is # or ; are ignored.</para>
+
+                <para>Note that both / and . are accepted as label
+                separators within sysctl variable
+                names. <literal>kernel.domainname=foo</literal> and
+                <literal>kernel/domainname=foo</literal> hence are
+                entirely equivalent.</para>
+
+                <para>Each configuration file shall be named in the
+                style of <filename>&lt;program&gt;.conf</filename>.
+                Files in <filename>/run/</filename> override files
+                with the same name in <filename>/usr/lib/</filename>.
+                Files in <filename>/etc</filename> override files with
+                the same name in <filename>/run/</filename> and
+                <filename>/usr/lib/</filename>. Packages should
+                install their configuration files in
+                <filename>/usr/lib/</filename>. Files in
+                <filename>/etc/</filename> are reserved for the local
+                administrator, who may use this logic to override the
+                configuration installed by vendor packages. All
+                configuration files are sorted by their name in
+                alphabetical order, regardless in which of the
+                directories they reside, to guarantee that a specific
+                configuration file takes precedence over another file
+                with an alphabetically earlier name, if both files
+                contain the same variable setting.</para>
+
+                <para>If the administrator wants to disable a
+                configuration file supplied by the vendor the
+                recommended way is to place a symlink to
+                <filename>/dev/null</filename> in
+                <filename>/etc/sysctl.d</filename> carrying with the
+                same name.</para>
         </refsect1>
 
         <refsect1>