I would guest that there's actually 10 stitches involved -- you put five of them on the holder, knit five more stiches, then pick up the five from the holder.

But it's hard to tell without the pattern. You could see if that works out correctly with the total number of stitches you have in the row.

Read your pattern very carefully. This is an unusual abbreviation, and should have been explained at the start of the directions. My guess is a 5-stitch cable - hold 2sts in front,k2, p1, k2 from cable needle - but it is only a guess ... Will check my Aran library to see if I can find it.

Check out the link below where the author has designed a sock featuring, among other motiffs, a 5-stich "coin cable." She says that "the 1st and 5th stitches are crossed." As you can see in the pic of the sock, doing this does create sort of a "coin effect."

If the pic of your project includes this coin effect cable, that's probably what is meant. If so, the pattern should have explained it.

Here is a link that might be useful: 5-stitch coin cable