The Freemason code of conduct, virtue, God and geometry are some of the universal symbols of the Freemason's square, which is the combination of a ruler, a set of compasses joined together and the letter G. There is no international symbol for every Freemason order, but all of them use the universal symbol in one form or another. Freemasonry has many other symbols that have a wide variety of meanings, including rank or status, vows and ritualistic activities.
The ruler is a 90-degree angled device typically used in brick laying and stone masonry to ensure that the walls are constructed squarely. The Freemasons apply this to their members behavior in implying that it is a virtue to square a person's actions with the square of virtue. For the Freemason symbol the ruler is stood on its corner stretching upwards in the shape of the letter v. The architect's compasses are also in a v-shape but extending downward to cross the ends of the ruler and create a square turned up on one edge.
Inside of the square is the capital letter G, which is the third letter in the alphabet in many Semitic languages, and the number three has been used by many religions throughout history to refer to God. The two Masonic tools placed around God symbolizes the manner in which King Solomon built his temple. The square has also been used by Freemasons to symbolize morality where the compass represents boundaries.