Valuation Clause
  
You have a collection of rare salt and pepper shakers. You have them insured. However, the guy from the insurance company shows a good deal of skepticism about their worth. He referred to them as "just a bunch of tchotchkes."
So you work out a valuation clause in the insurance policy. This provision sets a value for an item being insured.
You and the insurance company work out ahead of time what something is worth, and document that number in the policy itself. Then premiums are set according to that valuation. That way, you don't have to debate the value of the item if something happens.