When a method declaration includes an extern modifier, the method is said to be an external method. External methods are implemented externally, typically using a language other than C#. Because an external method declaration provides no actual implementation, the method-body of an external method simply consists of a semicolon. The mechanism by which linkage to an external method is achieved, is implementation-defined. [Example: The following example demonstrates the use of the extern modifier in combination with a DllImport attribute that specifies the name of the external library in which the method is implemented: end example]