Inscriptions in Castel del Monte

What is the meaning of the inscriptions on the walls of Castel del Monte? Are they perhaps to be interpreted - as some have supposed - in an esoteric key? Not at all.
The epigraphic and paleographic analysis, which studies the graphic signs and the techniques used to create inscriptions, has dated them to the 16th century, a period much more recent than the death of Emperor Frederick II of Swabia, which occurred in 1250. These scientifically and methodologically sound studies demonstrate the inscriptions are from ancient restoration interventions. Since the Middle Ages, in fact, a widespread practice in civil construction has been to affix epigraphs at the end of renovation works.
An inscription states (although in a very brief form) that Master Pace Surdo of Barletta completed the work on September 3rd, 1566. As Barletta documents reveal, "Master Pace" carried out building works in the area between 1551 and 1576.
In another (also in Latin and with many abbreviations) we read, however, that the illustrious Don Giovanni de China of Barletta had the castle repaired on March (or May) 8th, 1566. This individual, also attested to in Barletta between 1569 and 1583, was therefore likely the client of the restoration works conducted by the aforementioned «Mastro Pace».