jtreg allows for various test actions - "main", "testng", "junit", "shell", "applet". Certain projects that use jtreg to run tests may want to prevent test definitions that introduce specific test actions. For example, the JDK project might want to prevent "applet" test actions from being written. It would be good to allow such projects to configure (either in TEST.ROOT or TEST.properties) the actions they want to disallow. That way any new tests that introduce such test definitions will cause the test to error out and prevent such tests from being introduced.