In post #549 here I answered:
And then I was surprised by the comment of Tom, asking how the pairing was done. Well, I thought that I had discussed it in some thread in BSM, but after looking at it, it seems that I did only a few sparse remarks here and there. On other hand, people was not liking to interrupt the flow of the thread and I have been either contacted privately or suggested to open a new thread. So here it is. The development can be traced in some draft papers...