I agree with what trvvn5 said. This sure doesn't sound like any standard way to write out 'whatever' it is they want you to do and there should be somewhere in the book that they tell you what they mean.
I've never heard of slipping one, knitting 2 and then slipping the one slipped stitch over the 2 knits (not that that may not be exactly what they want). And why would they write it out that way, unless they told you somewhere what they meant? That is in no book I have.
Sue, you may be right, (I've learned that you are a little psychic when it comes to knitting
) but I've only seen sk2p and that means sl 1, K2tog
as you said before and psso, and then the p2 doesn't follow because it seems that would mean pass the 2 slipped stitches over and there there were not 2 slipped stitches to begin with.
If that book doesn't tell somewhere what they mean, it is not a very good book.
VioletStorm, how are you coming with this? How many stitches do you start out with and how many are you supposed to end up with? If you give us the instructions for the whole row maybe we could see how the numbers work out better. Maybe you found the spot in the book where it explains it when you looked in the spots trvvn5 suggested. Let us know how it comes out.