UML is being used as the universal technique for modeling object-oriented applications across a wide range of domains. Developing a truly adequate uniform modeling technique in the face of these diverse domains seems an unsolvable quest and contrasts domain specific software engineering activities. Recently, many adaptations to UML have been made to reflect a domain's world view. These adaptations often exceed the UML's own extension mechanisms and result in yet another urban UML slang. However, domain-specifically adapting the UML metamodel becomes increasingly important in the context of model checking and code generation mechanisms. Therefore solutions should be found to fully support metamodeling within the UML and UML CASE tools. The paper discusses and evaluates the UML's inherent as well as proprietary metamodeling approaches and provides domain driven ideas for a meta-modeling approach for a diversely used Unified Modeling Language.