C'est-à-dire « cépages interdits ». According to an article I just read, there are six grapes varietals that are "outlawed" in French wine-making. Apparently, the grapes can be grown but they can't be made into wine. It's not really clear why. The ban dates back to 1935.
One day years ago I was talking to a neighbor who has about 15 acres of vines up behind our house. I don't know if I brought up the subject of outlawed varietals, or if he did. Either way, he told me that one of his fellow vignerons had a row of such grapes planted among his "legal" vines. He treated the news like a big secret, but he told me more or less where the banned grapes were planted.
Why are these varietals — clinton, noah, jacquez, herbemont, othello, isabelle — unfit to be turned into wine? People whisper that the wine made from them would drive people crazy, the way it was rumored that absinthe did. Others says wine made from them just wouldn't taste good. There is some evidence that the ban might date back to the 19th-century importation of vines from North America that brought the phylloxera scourge to French vineyards and nearly killed the wine-making business here.
I don't know what the grapes in my photos here are, but they are the ones. I've tasted a grape of each color and I don't feel any crazier than I did before. Here's a link to the article (in French) that I read this morning.