Dots are were the lines intersect in a corner. Yes, mark all corners were the lines intersect with a "dot". You can punch a hole in your plastic templates or you can also do what my friend does, and mark the back of all pieces of the block with all the 1/4 seam lines; remember where the lines interect with one another is the "dot" or corner I speak of...hope this helps. Others on QB have also noted to stop on that dot to make the Y seams work right.