man: document about NAMING_REPLACE_STRICTLY network interface naming policy

Follow-up for b4d885f0e861b2d1bb5a62311c61a96f5222b026 and
068b0f77289411ef9f92f5d701759e98145a06e4.

diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml
index bc1ff7876d90b40a290fe3b67b1755c2de10b85b..6c14810a3e21cc897af498bf9ad627941110472d 100644 (file)
--- a/man/systemd.net-naming-scheme.xml
+++ b/man/systemd.net-naming-scheme.xml
@@ -381,7 +381,12 @@
           <para>Some firmware and hypervisor implementations report unreasonable high numbers for the onboard
           index. To prevent the generation of bogus onbard interface names, index numbers greater than 16381
           (2^14-1) were ignored. For s390 PCI devices index values up to 65535 (2^16-1) are valid. To account
-          for that, the limit is increased to now 65535.</para></listitem>
+          for that, the limit is increased to now 65535.</para>
+
+          <para>The udev rule <varname>NAME=</varname> replaces <literal>:</literal>,
+          <literal>/</literal>, and <literal>%</literal> with an underscore (<literal>_</literal>), and
+          refuses strings which contain only numerics.</para>
+          </listitem>
         </varlistentry>
 
       </variablelist>