Shape back neck and shoulders

I am finishing up the back of a man’s sweater. To shape back neck and shoulder I am to “K37 sts, turn and work on these sts for the first side of back neck.” (I understand this.) Next: “Dec 1st at neck edge on next 4 rows.” Does this mean to dec on knit side AND purl side? (Basically 2 decreases “at once”.) I thought dec was done only on knit side.

On the next four rows means just that so, yes, on knit and purl sides. It does seem unusual and will give you a very noticeable decrease slant on the neck. What pattern are you doing, can you give us a link? If you’re picking up stitches along the neckline to finish it moving the decrease in a stitch and working the edge stitch normally will make pu&k easier.