From here it's not private C3 with except local destination https://www.mapillary.com/app/?pKey=521926447415965

Same sign is placed on the entrance of https://www.openstreetmap.org/way/296879114 : https://www.mapillary.com/app/?pKey=2042344382936789

But there is also a strange C3 here : https://panoramax.openstreetmap.fr/#s=fp|s2|p856b7f82-ea21-4af3-888c-6c8de0fa4eac|c278.22/20.09/50|m18.09/50.886228/4.383124|bs
(nothing in the another direction)

How to interpret this ? 
