add_field (node, "revision", include_revision);
add_field (node, "time", include_time, enum_2_string (time_format));
add_field (node, "date", include_date, enum_2_string (date_format));
add_field (node, "revision", include_revision);
add_field (node, "time", include_time, enum_2_string (time_format));
add_field (node, "date", include_date, enum_2_string (date_format));