A more thorough explanation:

Definition: Half-mark is a term used in historical legal documents. It refers to a sum of money equal to six shillings and eight pence. In a writ of right, the demandant was required to tender half-mark to force them to prove seisin.

Example: In medieval England, if someone wanted to claim ownership of a piece of land, they would have to file a writ of right. To do so, they had to pay half-mark to the court. This payment was meant to ensure that the claimant had a legitimate right to the land and was not making a false claim.

Explanation: The example illustrates how half-mark was used in a legal context. It was a form of payment required to initiate legal proceedings and ensure that the claimant had a legitimate claim. The use of half-mark helped prevent false claims and ensured that only those with a valid claim could pursue legal action.