Quarantine Flags

These flags can be used on land during emergency situations such as self quarantine during the COVAD-19 pandemic

The Quarantine Flag, also known as the Q International Signal Flag, has historically been used on boats to warn of infectious diseases. In modern times, the L International Signal Flag has replaced the Q flag. These flags can also be used on land during emergency situations.

Reference https://www.maritimeprofessional.com/blogs/post/quarantine-flag-13441