used for each column.
         Each must presently be zero (text) or one (binary).
         All must be zero if the overall copy format is textual.
        </para>
       </listitem>
      </varlistentry>
     </variablelist>
    </listitem>
   </varlistentry>

   <varlistentry id="protocol-message-formats-CopyBothResponse">
    <term>CopyBothResponse (B)</term>
    <listitem>
     <variablelist>
      <varlistentry>
       <term>Byte1('W')</term>
       <listitem>
        <para>
         Identifies the message as a Start Copy Both response.
         This message is used only for Streaming Replication.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int32</term>
       <listitem>
        <para>
         Length of message contents in bytes, including self.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int8</term>
       <listitem>
        <para>
         0 indicates the overall <command>COPY</command> format
         is textual (rows separated by newlines, columns
         separated by separator characters, etc.). 1 indicates
         the overall copy format is binary (similar to DataRow
         format). See <xref linkend="sql-copy"/> for more information.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int16</term>
       <listitem>
        <para>
         The number of columns in the data to be copied
         (denoted <replaceable>N</replaceable> below).
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int16[<replaceable>N</replaceable>]</term>
       <listitem>
        <para>
         The format codes to be used for each column.
         Each must presently be zero (text) or one (binary).
         All must be zero if the overall copy format is textual.
        </para>
       </listitem>
      </varlistentry>
     </variablelist>
    </listitem>
   </varlistentry>

   <varlistentry id="protocol-message-formats-DataRow">
    <term>DataRow (B)</term>
    <listitem>
     <variablelist>
      <varlistentry>
       <term>Byte1('D')</term>
       <listitem>
        <para>
         Identifies the message as a data row.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int32</term>
       <listitem>
        <para>
         Length of message contents in bytes, including self.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int16</term>
       <listitem>
        <para>
         The number of column values that follow (possibly zero).
        </para>
       </listitem>
      </varlistentry>
     </variablelist>

     <para>
      Next, the following pair of fields appear for each column:
     </para>

     <variablelist>
      <varlistentry>
       <term>Int32</term>
       <listitem>
        <para>
         The length of the column value, in bytes (this count
         does not include itself).  Can be zero.
         As a special case, -1 indicates a NULL column value.
         No value bytes follow in the NULL case.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Byte<replaceable>n</replaceable></term>
       <listitem>
        <para>
         The value of the column, in the format indicated by the
         associated format code.
         <replaceable>n</replaceable> is the above length.
        </para>
       </listitem>
      </varlistentry>
     </variablelist>
    </listitem>
   </varlistentry>

   <varlistentry id="protocol-message-formats-Describe">
    <term>Describe (F)</term>
    <listitem>
     <variablelist>
      <varlistentry>
       <term>Byte1('D')</term>
       <listitem>
        <para>
         Identifies the message as a Describe command.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry>
       <term>Int32</term>
       <listitem>
        <para>
         Length of message contents in bytes,