I was a dealer and have been a collector and afficionado for fifteen years, but I have never before seen tis detail on a suit. It seems to be late thirties or forties. It is a kind of pleat in the front of the jacket. Frankly, it isn't particularly flattering, which is why it never caught on I guess. It is a suit at a local vintage shop. Not my size and not cheap. Nice suit otherwise, but not for me. But I thought I would share a pic anyway. Damn camera phones don't shoot so well in the dark.