A mass market in reusable components demands a high level of component quality, testing being a crucial part of software quality assurance. For components modelled in UML there are significant advantages to using UML also for the test description language. Since we wish to describe tests of non-trivial temporal ordering properties, we define our test description language based around UML interaction diagrams, seeking inspiration from the work on conformance testing of telecom protocols. We aim at a fully integrated approach which can be captured in a UML component testing profile.