World Rally Championship - News - Revealed: Citroen's Finnish secret weapon
OK, now it is clearer, basically Citroen has made what Reiger started and all others copied since, turned the damper upside down. The primary benefit from this is less friction, due to separate tubes, one tube for the piston, and one for guidance of the strut. The other benefit is improved durability(but this has never been an issue for Citroen before..)
So actually the Greeks here were right, Citroen just now are using same technics as Ford has for years. Just shows how good everything else is on that car!