- <para>For types "s" and "g" (unicode string or signature), the pointer may be
- <constant>NULL</constant>, which is equivalent to an empty string. See
- <citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- for the precise interpretation of those and other types.</para>
-