I honestly have no idea what they are, Garp. Its hard to know if they are naturally tangy or if they are pickled.
They aren't wrinkled like normal capers and they look and feel more like turgid fruit berries than anything else. I've had them in curries before, maybe even baltis from different T/As. I don't know enough to say either way.
I'm sure I've seen comment on the forum about them previously, but I can't think where or when, and I can't find any images or info on the web. Someone will know, I'm sure.