A more thorough explanation:

Definition: Jus stapulae is a legal term that refers to a town's right or privilege to stop imported goods and force them to be sold in its own market. This term comes from the Latin phrase "right of staple."

• A town may have jus stapulae over certain goods, such as wool, leather, tin, lead, butter, or cheese. This means that any merchants who bring these goods into the town must offer them for sale in the local market before selling them elsewhere.
• In the past, the Crown would appoint certain towns as exclusive markets for staple products. These towns would have jus stapulae over those products, which helped to regulate trade and ensure fair prices.
• In modern patent law, a "staple" refers to an unpatented material that is used in a patented product or process, but also has other practical uses. For example, a company may hold a patent on a specific type of ink, but they cannot control the market for the paper that the ink is used on, as paper is considered a nonstaple.

These examples illustrate how jus stapulae has been used throughout history to regulate trade and protect local markets. By giving towns the right to control the sale of certain goods, it helped to prevent monopolies and ensure fair competition. In modern patent law, the concept of staples is used to prevent patent holders from gaining too much control over the market for their products.