1.8.4: Docblock Annotations

@magentoDbIsolation runs the test inside a transaction. This ensures the database is reset. Note this is automatically enabled if you use @magentoDataFixture (another reason to do so).
@magentoAppArea determines in which area this test runs.
@magentoConfigFixture sets a store configuration value.
@magentoCache enables or disables the cache.

Further reading: