…which was enforced by the church courts.
Essentially, if you had sex outside of wedlock, often with a prostitute (hence the “buttock” part, which was a slang for prostitute), and you were a Presbyterian in Scotland, you would often be given the choice of the Stool of Repentance or paying buttock-mail to stop from having to stand on a stool in front of everyone and get berated by your local minister for your lustful actions.
While the latter, perhaps, doesn’t sound so bad to modern thinking compared to having to pay a hefty tax to keep things quiet, without the option of buttock-mail, or if one couldn’t afford it, people are known to have killed themselves rather than have to face the Stool of Repentance and the “fornicator” label that would follow them in the aftermath.
