An element of an expression that refers to the value of a field, control, or property. For example, Forms![Orders]![OrderID] is an identifier that refers to the value in the OrderID control on the Orders form.
Identifiers can be presented in two ways: qualified or nonqualified. A qualified identifier, such as Forms![Orders]![Orders Subform].Form![UnitPrice], refers to the same data object within an active database regardless of the context. A nonqualified identifier, such as [Orders Subform].Form![UnitPrice], can refer to different data objects within an active database depending on the context.