For a fortnight, the red carpet at the Cannes Film Festival becomes the biggest style showcase outside the Paris catwalks, and the organizers of the gala screenings at the Palais have standards that, they insist, must be kept. For this, they have deputized fashion police.After filmgoers are admitted into the front gate of the theater, they are given the once-over. If the outfit is not up to standards, they are not admitted to the theater or made to alter the ensemble. Allowances, however, are made for the artistes. Considering the long list of fashion faux pas by them over the past five decades (Sharon Stone, anyone?), they’d better be given some leeway.