Explanation:

- Stay of suit: This is when a court temporarily halts proceedings in a case. It might be issued for various reasons such as awaiting a related decision or complying with a prerequisite action.

- Injunction: A legal order that prevents a party from doing something, like continuing an action that infringes on another's rights. It’s a remedy that prevents future harm.

- Caveat: ?? This is a formal notice to a court or public authority to suspend a proceeding until the notifier is given a chance to appear. It ensures the applicant gets notified before any action is taken.

- Letter of request: A formal written request through which a court requests assistance from a foreign court. It usually involves serving legal documents or obtaining evidence abroad.