what does the keystones inscription signify in the mark degree and where did it come from

The inscription surrounding the central mark on the keystone consists of the letters H. T. W. S. S. T. K. S. arranged in a circle 1. These letters form the initials of a mystical sentence in the vernacular tongue, which is also rendered in Hebrew letters under certain jurisdictions, such as the Supreme Grand Chapter of Scotland 1.

Symbolically, the white stone bearing an inscription draws upon ancient traditions of judgment, distinction, and hospitality. In ancient Greek and Roman courts, a white stone deposited in a ballot signified acquittal or approval, giving rise to its use as an emblem of absolution, honors, and rewards 1. It was also recognized as a token given to victors in athletic or gladiatorial contests 1. Scripturally, the concept rests on Revelation 2:17, which promises a white stone with a new name written upon it that is known only to him who receives it 1.

In its functional and social character within the degree, the inscribed keystone or Mark token descends from the ancient practice of the *tessera hospitalis* or pledge of hospitality 1. Among the ancients, a token or broken die was exchanged between friends so that presenting it at a future time would renew their fellowship and secure aid in foreign countries 1. In Mark Masonry, the token acts as a sacred pledge of friendship and brotherly love 1. A Mark Master may pledge his Mark to a brother to claim assistance, but a strict rule of the Order forbids pledging it a second time until the original pledge has been redeemed, preventing improper use of the token 1.

Regarding the ceremonial placement of the rejected stone motif, F. Yates notes that the symbolism of the rejected keystone was not present in the original Master Mark Mason's degree, but was later introduced by Thomas Smith Webb from an undetermined source when compiling his ritual 1.