Hello, According to my archive digging, this issue comes up again and again. I was just wondering whether somebody had code lying around for a Deming Regression or a MLFR method for this, which I might peruse. I came across a post from Brian Ripley stating that something like it was close to be included into MASS a couple of times and was wondering whether it made the cut there (or elsewhere) in the meantime ... Any hint is greatly appreciated. Joh