An annotation is a message that is associated with code. This is different from the metadata that may be associated with a test because an annotation can apply to code elements that are not tests.

For example, if an error occurs while parsing the declarative attribute structure that defines a test, then the test itself may not be added to the test tree. Instead, the Pattern Test Framework will associated an error annotation with the point of definition of the test. This annotation is displayed by the test runner as an error. Some test runners, such as the ReSharper test runner, will actually highlight the annotated element in the IDE using an error stripe.

This attribute makes it possible to add annotations to code elements declaratively.

Note: The annotation will only be added if the associated code element is traversed during the normal sequence of test exploration.