received and written to disk
             in the standby.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int64</term>
           <listitem>
            <para>
             The location of the last WAL byte + 1 flushed to disk in
             the standby.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int64</term>
           <listitem>
            <para>
             The location of the last WAL byte + 1 applied in the standby.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int64</term>
           <listitem>
            <para>
             The client's system clock at the time of transmission, as
             microseconds since midnight on 2000-01-01.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Byte1</term>
           <listitem>
            <para>
             If 1, the client requests the server to reply to this message
             immediately. This can be used to ping the server, to test if
             the connection is still healthy.
            </para>
           </listitem>
          </varlistentry>
         </variablelist>
        </listitem>
       </varlistentry>

       <varlistentry id="protocol-replication-hot-standby-feedback-message">
        <term>Hot standby feedback message (F)</term>
        <listitem>
         <variablelist>
          <varlistentry>
           <term>Byte1('h')</term>
           <listitem>
            <para>
             Identifies the message as a hot standby feedback message.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int64</term>
           <listitem>
            <para>
             The client's system clock at the time of transmission, as
             microseconds since midnight on 2000-01-01.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int32</term>
           <listitem>
            <para>
             The standby's current global <literal>xmin</literal>, excluding the
             <literal>catalog_xmin</literal> from any replication slots. If both
             this value and the following <literal>catalog_xmin</literal>
             are 0, this is treated as a notification that hot standby feedback
             will no longer be sent on this connection. Later non-zero messages
             may reinitiate the feedback mechanism.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int32</term>
           <listitem>
            <para>
             The epoch of the global <literal>xmin</literal> xid on the standby.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int32</term>
           <listitem>
            <para>
             The lowest <literal>catalog_xmin</literal> of any replication
             slots on the standby. Set to 0 if no <literal>catalog_xmin</literal>
             exists on the standby or if hot standby feedback is being
             disabled.
            </para>
           </listitem>
          </varlistentry>

          <varlistentry>
           <term>Int32</term>
           <listitem>
            <para>
             The epoch of the <literal>catalog_xmin</literal> xid on the standby.
            </para>
           </listitem>
          </varlistentry>
         </variablelist>
        </listitem>
       </varlistentry>
      </variablelist>
     </listitem>
    </varlistentry>

    <varlistentry id="protocol-replication-start-replication-slot-logical">
     <term><literal>START_REPLICATION</literal> <literal>SLOT</literal> <replaceable class="parameter">slot_name</replaceable> <literal>LOGICAL</literal> <replaceable class="parameter">XXX/XXX</replaceable> [