man: describe naming schemes in a new man page

I decided to make this a separate man page because it is freakin' long.
This content could equally well go in systemd-udevd.service(8), systemd.link(5),
or a new man page for the net_id builtin.

v2:
- rename to systemd.net-naming-scheme
- add udevadm test-builtin net_id example

1 files changed, 8 insertions, 12 deletions

diff --git a/man/systemd-udevd.service.xml b/man/systemd-udevd.service.xml
index cf8087ccb3..c267bb2b11 100644
--- a/man/systemd-udevd.service.xml
+++ b/man/systemd-udevd.service.xml
@@ -171,15 +171,12 @@
         <term><varname>net.naming-scheme=</varname></term>
         <listitem>
           <para>Network interfaces are renamed to give them predictable names when possible (unless
-          <varname>net.ifnames=0</varname> is specified, see above). The names are derived from various
-          device metadata fields. Newer versions of <filename>systemd-udevd.service</filename> take more of
-          these fields into account, improving (and thus possibly changing) the names used for the same
-          devices. With this kernel command line option it is possible to pick a specific version of this
-          algorithm. It expects a naming scheme identifier as argument. Currently the following identifiers
-          are known: <literal>v238</literal>, <literal>v239</literal>, <literal>v240</literal> which each
-          implement the naming scheme that was the default in the indicated systemd version. In addition,
-          <literal>latest</literal> may be used to designate the latest scheme known (to this particular
-          version of <filename>systemd-udevd.service</filename>).</para>
+          <varname>net.ifnames=0</varname> is specified, see above). With this kernel command line option it
+          is possible to pick a specific version of this algorithm and override the default chosen at
+          compilation time. Expects one of the naming scheme identifiers listed in
+          <citerefentry><refentrytitle>systemd.net-naming-scheme</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+          or <literal>latest</literal> to select the latest scheme known (to this particular version of
+          <filename>systemd-udevd.service</filename>).</para>
 
           <para>Note that selecting a specific scheme is not sufficient to fully stabilize interface naming:
           the naming is generally derived from driver attributes exposed by the kernel. As the kernel is
@@ -188,9 +185,8 @@
         </listitem>
       </varlistentry>
     </variablelist>
-    <!-- when adding entries here, consider also adding them
-         in kernel-command-line.xml -->
- </refsect1>
+    <!-- when adding entries here, consider also adding them in kernel-command-line.xml -->
+  </refsect1>
 
   <refsect1>
     <title>See Also</title>