Health letter
The health certificate is a term used in shipping .
In the 18th century, the health letter provided a kind of entry permit for ships returning from countries where diseases that could be transmitted to other people were rampant. When docking in the respective port, the captain of every ship that intended to anchor there had to be denied Show health certificate. If the skipper could not produce a health certificate, the entire ship's crew was usually quarantined .
Another name for the health letter is health passport .