Welcome to the Forum, harry. Where in Mass are you? I'm on the western border, along NY state. I am surveying a barn right now that has the same type of mark. It was made by a race knife. Some race knives have a leg that allows it to pivot and make a full or semi-circle. The barn I'm researching uses both semi, and full circles over a line, or two lines. From what I can see of this barn, the single line means it is the east post, and the double line means west. The second bent uses a single line, while the third uses two lines. I haven't been able to dig deep enough to see what other markings are used, as I have to pull some siding boards. I look forward to seeing more about this topic, as scribe markings are a point of interest for me.