I think it has to do with certain maneuver. I don't know the rest of the pattern instruction so I don't quite know how to help.
I would guess that whatever you have to do is involving only with the YO stitch and not with other stitch. (YO-st only = yarn over stitch only).
If you want me to look into it further, you can give me more instruction and I'm happy to help.
Hi I am crocheting a baby jacket and I am stuck please help me! The confused part is in Using C2 (C2-C1-C1-C1-C1), cont as folls – 3rd row – (1dc, 1ch)