Pattern is Dogosaurus Rex by Paton's. It's a Canadian pattern. It's basically a dog sweater with a spike edging like a Stegosaurus along the top back.
In the instructions, they say Yfwd = American YO.
However, I searched the archives here and found Yfwd (in this context) meaning to K1, YO without dropping st, K into 1st stitch, giving you 3 for 1.
The pattern says: K1, yfwd, K2. 4 sts.
2nd row knit
3rd row K1, yfwd, K3. 5 sts. (and continues like this until you have a big triangle and you cast off).
So I don't think the 3 in 1 thing is right, because then you don't have the right # of sts. BUT, what I am making is some triangular "spikes" for the stegosaurus spikes on the dog's back, and so why would they have holes in them? The pattern photo isn't that great but I don't think a plain YO making a hole is right either. :??