diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml
index bc1ff7876d9..6c14810a3e2 100644
--- 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>