What is Price-reporting agency, assessment window?

A price-reporting agency (PRA) is a publisher that assesses and publishes, every business day, the prices of physical commodities and related over-the-counter contracts from the bids, offers and trades it observes and from reports by market participants. An assessment window is a fixed daily period during which the agency collects bids, offers and trades that it then uses to set its assessment at the window’s closing time.