A more thorough explanation:

LETTRE DE CACHET

A lettre de cachet is a type of royal warrant that allows a person to be imprisoned without a trial. The term comes from the French words "letter with a seal."

During the reign of King Louis XVI of France, lettres de cachet were frequently used to silence political dissidents and other individuals who were seen as a threat to the monarchy. For example, the writer Voltaire was imprisoned for several months by a lettre de cachet.

Another example of a lettre de cachet being used was in the case of the Marquis de Sade, a French nobleman and writer who was imprisoned for his scandalous writings and behavior.

The examples illustrate how lettres de cachet were used to imprison individuals without a trial or due process. These warrants were often used to silence political dissidents or individuals who were seen as a threat to the monarchy or social order. The use of lettres de cachet was a controversial practice that was eventually abolished during the French Revolution.