Anon's I've just had a crazy thought.

You can't see the wood for the trees.

Look at the sticks on the ground.

The ones at the bottom are either Mu (blue & red) Lambda (red) or just a direction arrow.

The one above is Xi.

Xi is an interesting letter in greek as it signifies separation, detachment or leaving.

My first thought was that it could be something to do with your fraternity/sorority groups.