Yarn Over > Yarn Forward?

I found an old knitting book from 1973. I’m trying out a floral lace sample, and the book often uses the abbreviation YF, yarn forward. Is this the same thing as YO?

If it is, there’s one part I don’t understand. It says to YF, slip a stitch, and then k2tog. The working yarn is left where that YF is … meaning it has to pass over the slipped stitch to work the k2tog, and that doesn’t look right at all. Am I doing something wrong? (I guess I’ve gotta find out the YF > YO part first, haha.)

Yarn forward and yarn back are the same as yarn over, just more specific.

UK vs. US kind of thing.

Having that yarn where it is just may be part of the pattern. I would give it a chance and see how it looks after a few rows.