ORM (Object-Role Modeling) is a rich and well-known conceptual modeling method. As ORM has a formal semantics, reasoning tasks such as satisfiability checking of an ORM schema naturally arise. Satisfiability checking allows a developer to automatically detect contradicting constraints. However, no complete satisfiability checker is known for ORM. In this paper, we revisit existing patterns from literature that indicate unsatisfiability of ORM schemes i.e., schemes that cannot be populated, and we propose refinements as well as additions for them. Although this does not yield a complete procedure