A «tent» of foil placed loosely over turkey keeps it from browning too fast and may be removed when necessary to baste turkey. (bonappetit.com)
The top browns up really fast, so the foil keeps it from browning too much. (naturalsweetrecipes.com)
By the way, if you have leftover guacamole (or if you make it ahead of time) and want to keep it from browning as quickly as it usually does, here's a tip — save the avocado pits and keep them all in the (tightly sealed!) (iwasborntocook.com)