diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 7a5d1ea903..387db97a09 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1633,6 +1633,9 @@ include_dir 'conf.d'
         the value of <xref linkend="guc-maintenance-work-mem"/> should
         be used instead.  The setting has no effect on the behavior of
         <command>VACUUM</command> when run in other contexts.
+        This parameter can only be set in the
+        <filename>postgresql.conf</filename> file or on the server command
+        line.
        </para>
       </listitem>
      </varlistentry>
@@ -3692,7 +3695,8 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
         <varname>max_worker_processes</varname>.
        </para>
        <para>
-        The default value is 4.
+        The default value is 4. This parameter can only be set at server
+        start.
        </para>
       </listitem>
      </varlistentry>
@@ -3717,7 +3721,9 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
         <varname>max_logical_replication_workers</varname>.
        </para>
        <para>
-        The default value is 2.
+        The default value is 2. This parameter can only be set in the
+        <filename>postgresql.conf</filename> file or on the server command
+        line.
        </para>
       </listitem>
      </varlistentry>
@@ -8261,6 +8267,11 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         useful to disable the restart so that the clusterware can gain
         control and take any actions it deems appropriate.
        </para>
+
+       <para>
+        This parameter can only be set in the <filename>postgresql.conf</filename>
+        file or on the server command line.
+       </para>
       </listitem>
      </varlistentry>