What does three small rings in a triangle mean in a Swedish parish registers? In Sweden during the 18th and 19th century each parish had a "Husförhörslängd", a book tallying the people in the parish keeping track of how well they knew their biblical history, and if they had taken their communion. Very often in these books I find that some people have a marking of three small rings in a triangle. See enclosed picture. What does this marking mean? !Example of three rings marking

I happened on the answer:

!signs

Turns out it means the person has been vaccinated against smallpox, either by vaccine, or by "protective pox", which I think means cowpox.