or does not include the specified field.  Field values will normally
        not include a trailing newline. The caller should not free the
        result directly. It will be freed when the
        associated <structname>PGresult</structname> handle is passed to
        <xref linkend="libpq-PQclear"/>.
       </para>

       <para>
        The following field codes are available:
        <variablelist>
         <varlistentry id="libpq-pg-diag-severity">
          <term><symbol>PG_DIAG_SEVERITY</symbol></term>
          <listitem>
           <para>
            The severity; the field contents are <literal>ERROR</literal>,
            <literal>FATAL</literal>, or <literal>PANIC</literal> (in an error message),
            or <literal>WARNING</literal>, <literal>NOTICE</literal>, <literal>DEBUG</literal>,
            <literal>INFO</literal>, or <literal>LOG</literal> (in a notice message), or
            a localized translation of one of these.  Always present.
           </para>
          </listitem>
         </varlistentry>

         <varlistentry id="libpq-PG-diag-severity-nonlocalized">
          <term><symbol>PG_DIAG_SEVERITY_NONLOCALIZED</symbol></term>
          <listitem>
           <para>
            The severity; the field contents are <literal>ERROR</literal>,
            <literal>FATAL</literal>, or <literal>PANIC</literal> (in an error message),
            or <literal>WARNING</literal>, <literal>NOTICE</literal>, <literal>DEBUG</literal>,
            <literal>INFO</literal>, or <literal>LOG</literal> (in a notice message).
            This is identical to the <symbol>PG_DIAG_SEVERITY</symbol> field except
            that the contents are never localized.  This is present only in
            reports generated by <productname>PostgreSQL</productname> versions 9.6
            and later.
           </para>
          </listitem>
         </varlistentry>

         <varlistentry id="libpq-pg-diag-sqlstate">
          <term><symbol>PG_DIAG_SQLSTATE</symbol><indexterm
          ><primary>error codes</primary><secondary>libpq</secondary></indexterm></term>
          <listitem>
           <para>
            The SQLSTATE code for the error. The SQLSTATE code identifies
            the type of error that has occurred; it can be used by
            front-end applications to perform specific operations (such
            as error handling) in response to a particular database error.
            For a list of the possible SQLSTATE codes, see <xref
            linkend="errcodes-appendix"/>. This field is not localizable,
            and is always present.
           </para>
          </listitem>
         </varlistentry>

         <varlistentry id="libpq-pg-diag-message-primary">
          <term><symbol>PG_DIAG_MESSAGE_PRIMARY</symbol></term>
          <listitem>
           <para>
            The primary human-readable error message (typically one line).
            Always present.
           </para>
          </listitem>
         </varlistentry>

         <varlistentry id="libpq-pg-diag-message-detail">
          <term><symbol>PG_DIAG_MESSAGE_DETAIL</symbol></term>
          <listitem>
           <para>
            Detail: an optional secondary error message carrying more
            detail about the problem.  Might run to multiple lines.
           </para>
          </listitem>
         </varlistentry>

         <varlistentry id="libpq-pg-diag-message-hint">
          <term><symbol>PG_DIAG_MESSAGE_HINT</symbol></term>
          <listitem>
           <para>
            Hint: an optional suggestion what to do about the problem.
            This is intended to differ from detail in that it offers advice
            (potentially inappropriate) rather than hard facts.  Might
            run to multiple lines.
           </para>
          </listitem>
         </varlistentry>

         <varlistentry id="libpq-pg-diag-statement-position">
          <term><symbol>PG_DIAG_STATEMENT_POSITION</symbol></term>
          <listitem>