mysterium hoc arcanum

Located to the left door jamb of the Baptistery of Pisa, one of the other ensemble of buildings in the Piazzia dei Miracoli often upstaged by the cathedral’s campanile, the structure designed by architect Diotisalvi and built from 1153 to 1363 contains an undeciphered epigraph, which while representing an unknown script, is not unique—lost though having

appeared in Lucca and other places in Tuscany—is suggested to in a sense a kind of gamification to hunt for such mystery inscriptions and debate, contemplate what they might mean without any definitive interpretation established. Courtesy of one of the commentators, here is the puzzle to solve.