The mark consists of stylized letters HRT encircled by and intersecting with a circular element where a serif at the bottom left of the H intersects with the circular element, the vertical stroke of the right side of the H and vertical stroke of the left side of the R are shared, the top stroke of the R and the T are shared and continuous across the top of the R and the T, a serif at the bottom right of the R and the bottom left of the T are connected, the continuous top stroke of the R and T extend into and intersect with the circular element where the circular element comprises a bold line continuously diminishing clockwise from the intersection of the top stroke of the R and T until vanishing at a point just before the intersection of the circular element with the serif at the bottom left of the H and the circular element begins again as a bold line where the serif at the bottom left of the H intersects with the circular element and the bold line continuously diminishes clockwise from the intersection of the serif at the bottom left of the H until vanishing at a point just before the intersection of the circular element with the top stroke of the R and T.