Some golfers notice that on pro golf broadcasts, and on some websites where the scorecards of tour players are re-created, those cards include some holes where the stroke total has been circled or squared. The circles represent below-par holes and the squares above-par holes. A score that is neither circled nor squared is a par.
We're not fans of this method, because it creates a sloppy scorecard. But especially for beginners and mid- and high-handicap golfers, it's pretty pointless. After all, if you're in these categories, you won't be making many (or probably any) birdies; you might not even be making many pars. Your scorecard will be full of nothing but numbers with squares around them.
But because it's a PGA Tour thing, some golfers like to do it this way. So one circle represents a birdie, and a score circled twice represents an eagle or better. One square represents a bogey, while a score with two squares drawn around it represents a double-bogey or worse.