The mark consists of the white letters, F, U, S and E, arranged from left to right, each enclosed in a circle of a different color. The F in enclosed in a circle of blue in gradations ranging from light blue to dark blue. The U is enclosed in a circle of green in gradations ranging from light green to dark green. The S is enclosed in a circle of black in gradations ranging from black to gray. The E is enclosed in a circle of purple in gradations ranging from light purple to dark purple. The circles enclosing the letters are connected by three black arrows, with one arrow between each of the letter pairs F-U, U-S and S-E. Each of the circles enclosing the letters is surrounded by three concentric gray circles. All of the foregoing elements are arranged in an arc, with the lowest point of the arc being the midpoint. All of the foregoing elements are superimposed on several gray arcs that follow the arc of the elements.