notin
$tax_query = array( 'relation' => 'AND', array( 'taxonomy' => 'kategoria_ref', 'terms' => 'w przygotowaniu', 'operator' => 'NOT IN', ), );
$tax_query = array( 'relation' => 'AND', array( 'taxonomy' => 'kategoria_ref', 'terms' => 'w przygotowaniu', 'operator' => 'NOT IN', ), );