What does it mean - clam juice reserve?

Clam juice reserve refers to a concentrated liquid made from clams, typically used as a flavoring or ingredient in cooking, particularly in seafood dishes and soups. It is often made by simmering clams in water to extract their natural flavors and then straining the liquid. The term "reserve" may imply that this juice is set aside for later use or is of a higher quality, possibly indicating a specific selection of clams or a particular method of preparation.