diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index ecd9843a68b..224e4d05ee9 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1382,6 +1382,11 @@ include_dir 'conf.d'
         want to set this to a higher value if all software components can
         support the newer protocol versions.
        </para>
+
+       <para>
+        This parameter can only be set in the <filename>postgresql.conf</filename>
+        file or on the server command line.
+       </para>
       </listitem>
      </varlistentry>
 
@@ -1400,6 +1405,11 @@ include_dir 'conf.d'
         useful for testing or if some component has issues working with a
         newer protocol.
        </para>
+
+       <para>
+        This parameter can only be set in the <filename>postgresql.conf</filename>
+        file or on the server command line.
+       </para>
       </listitem>
      </varlistentry>
 
@@ -1740,6 +1750,9 @@ 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>
@@ -4448,7 +4461,8 @@ 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>
@@ -4473,7 +4487,9 @@ 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>
@@ -9143,6 +9159,11 @@ 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>