What are the esoteric interpretations of the Triple Tau in the Holy Royal Arch degree?

Old English Royal Arch lectures interpreted the Triple Tau geometrically, stating that its intersections form angles in five regular combinations whose sum in right angles equals the five Platonic solids representing the four elements and the sphere of the universe 1.

Albert Mackey proposed a scriptural reading based on the Prophet Ezekiel, where the tau cross serves as a mark distinguishing those saved for their sorrow over sin 1. In his view, the symbol acts in the Royal Arch as a mark designating and separating those who know and worship the true name of God from those ignorant of that mystery 1.

Robert Lomas emphasizes its theological aspect, noting that the emblem symbolizes the threefold nature of a single Deity who is one and yet three, with each of the three Persons possessing attributes of the other two 2. He describes its form as arising from the union of three separate tau crosses—such as those associated with the three ruling officers of a lodge—joined together into a unified emblem of Divinity 2.