A more thorough explanation:

Black Acts refer to a set of laws passed by the Scottish Parliament between 1535 and 1594. These laws were recorded in a book printed in black letter.

For example, one of the Black Acts was the Witchcraft Act of 1563, which made it a crime to practice witchcraft or consult with witches. Another Black Act was the Act of Proscription of 1746, which banned the wearing of traditional Scottish clothing and playing of bagpipes.

These examples illustrate how the Black Acts were used to control and suppress certain practices and behaviors deemed unacceptable by the Scottish government. The laws were often harsh and punitive, with severe penalties for those who broke them.