man: document that ProtectHostname= disables hostname change notifications

diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index b8843f1ea0bb7e869de35d3db6347189f3596df1..19c7b26bcee3571a9146daf8f50e05ce9ed9d278 100644 (file)
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -1135,9 +1135,13 @@ BindReadOnlyPaths=/var/lib/systemd</programlisting>
         <listitem><para>Takes a boolean argument. When set, sets up a new UTS namespace for the executed
         processes. In addition, changing hostname or domainname is prevented. Defaults to off.</para>
 
-        <para>Note that the implementation of this setting might be impossible (for example if UTS namespaces are not
-        available), and the unit should be written in a way that does not solely rely on this setting for
-        security.</para></listitem>
+        <para>Note that the implementation of this setting might be impossible (for example if UTS namespaces
+        are not available), and the unit should be written in a way that does not solely rely on this setting
+        for security.</para>
+
+        <para>Note that when this option is enabled for a service hostname changes no longer propagate from
+        the system into the service, it is hence not suitable for services that need to take notice of system
+        hostname changes dynamically.</para></listitem>
       </varlistentry>
 
       <varlistentry>