The mark consists of The literal element of the letter H stands for Horizon. The literal element of the line under the letter H stands for the word Line. The letter H and the line represent the words Horizon Line. The spelled-out words Horizon and Line are the written out format of the H element and the line element. The words represent the term horizon line. Next to the word line is a degree symbol. The degree symbol is there to symbolize that a horizon line can occur at any degree of latitude and longitude.