(Technical reply back to @gwenvaneijk: despite it's name the WAMCA covers all class action procedures, wether damage is claimed or not. It's a cover-all act for collective procedures that combines the possibilities to claim e.g. a declaration of right and *can* include damages. See the appeal judgment I cited and second bullet point under 2 on page 1 of the explanatory memorandum that accompanied the WAMCA).