yellow jack

While all of Italy is under lockdown conditions forming a cordon sanitaire to medically isolate potential carriers and stop the spread of sickness, it’s worth noting that the term quarantine itself is owing to the Venetian thalassocracy and the best-practises that the city modeled.
From the local dialectical form of quaranta giorni, it refers to the forty day period that ships, cargo and compliment were held in abeyance in order to not transmit the plague, which in a decade’s time in the mid-fourteenth century had claimed thirty percent of the Eurasian population. The safeguard was first developed in Ragusa (Dubrovnik) and confined visitors to an outlying island for a period of thirty days (a trentine) before granting them admission. After avoid the Black Death’s first iteration, the government of Venice moved to extend the restriction by ten more days, which happened to match the course of illness from the bubonic plague from exposure to incubation through to the contagious phase and recovery. In the language of maritime signal flags, the solid yellow banner, Q for Quebec, historically indicated quarantine but now certifies that the vessel is free from communicable disease and requests free pratique—that is, to enter a port. Whereas the above semaphore whilst in harbour, L for Lima, means the ship is under quarantine.