The mark consists of The mark consists of the capital letter H, with the left and right upper ends of the letter each terminating in flared portions and the left and right lower ends of the letter each forming a pair of opposed loops before terminating in respective first and second tails. The left loop of the left lower letter end is located upwardly of and overlaps the left loop of the right lower letter end while the right loop of the right lower letter end is located upwardly of and overlaps right loop of the left lower letter end. The tail of the left lower letter end (i.e., the first tail) terminates in a rightwardly-directed spiral centrally located below the opposed loops of both of the lower letter ends. The tail of the right lower letter end (i.e., the second tail) terminates in a rightwardly and downwardly-direction near the above-right of the spiral of the left lower letter end and near the below-left of the right loop of the left lower letter end. A leftwardly-directed third tail extends upwardly from between the opposed loops of the right lower letter end, with the tail terminating between the left and right lower letter ends below the cross-member of the letter. A downwardly-directed fourth tail extends centrally from the lower end of the spiral of the left lower letter end. The design element comprising the letter H, opposing loops and tails is centrally located within a pentagon, with an upper point of the pentagon centrally located above the left and right upper letter ends, and a lower point of the pentagon centrally located below the fourth tail.