diff --git a/man/sd_notify.xml b/man/sd_notify.xml
index a6a9a9bed8..0f2f931477 100644
--- a/man/sd_notify.xml
+++ b/man/sd_notify.xml
@@ -258,7 +258,8 @@
         <term>BUSERROR=…</term>
 
         <listitem><para>If a service fails, the D-Bus error-style error code. Example:
-        <literal>BUSERROR=org.freedesktop.DBus.Error.TimedOut</literal></para>
+        <literal>BUSERROR=org.freedesktop.DBus.Error.TimedOut</literal>. Note that this assignment is
+        currently not used by <command>systemd</command>.</para>
 
         <xi:include href="version-info.xml" xpointer="v233"/></listitem>
       </varlistentry>
@@ -266,8 +267,15 @@
       <varlistentry>
         <term>EXIT_STATUS=…</term>
 
-        <listitem><para>If a service exits, the return value of its <function>main()</function> function.
-        </para>
+        <listitem><para>The exit status of a service or the manager itself. Note that
+        <command>systemd</command> currently does not consume this value when sent by services, so this
+        assignment is only informational. The manager will send this notification to <emphasis>its</emphasis>
+        notification socket, which may be used to to collect an exit status from the system (a container or
+        VM) as it shuts down. For example,
+        <citerefentry project='debian'><refentrytitle>mkosi</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+        makes use of this. The value to return may be set via the
+        <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+        <command>exit</command> verb.</para>
 
         <xi:include href="version-info.xml" xpointer="v254"/></listitem>
       </varlistentry>
@@ -434,8 +442,10 @@
       </varlistentry>
     </variablelist>
 
-    <para>It is recommended to prefix variable names that are not listed above with <literal>X_</literal> to
-    avoid namespace clashes.</para>
+    <para>The notification messages sent by services are interpreted by the service manager. Unknown
+    assignments may be logged, but are otherwise ignored. Thus, it is not useful to send assignments which
+    are not in this list. The service manager also sends some messages to <emphasis>its</emphasis>
+    notification socket, which are then consumed by the machine or container manager.</para>
   </refsect1>
 
   <refsect1>