It is sometimes called the "cross potent" from its shape, "potent" being an old English word for a crutch. It is then said to signify the Cross as the sure support of all who trust in it.
Four tau-crosses joined foot to foot form a "Jerusalem cross." Such a cross was part of the armorial bearing of the first Christian king of Jerusalem. The four conjoined tau-crosses, forming a Greek cross, are said to be symbolical of the displacement of the Old Testament by the New, the Law by the Gospel.
Jerusalem cross
Many forms of the cross originated in the wars of the Cross, the crusaders in their eastward wanderings engrafting many variations upon the original Greek cross. Many of these heraldic crosses tell some story of religious feeling. In their varied and fanciful forms the simple faith and holy purpose out of which they sprang may yet be traced.
The "cross moline" is so named from resemblance to the moline, or crossed iron, in the center of the upper millstone. Its ends are divided and curved backward. As they are turned in all directions, they are said to express the universal diffusion of the blessings of the Cross; or, as they decline both to the right and the left, they express willingness to do exact justice and give to all their due.
