Designing is a complex process. Where this process involves multiple participants located in different places, digital tools for supporting this process are indispensable. However, the use and creation of tools for supporting design processes necessary entails intervening in or manipulating the process it intends to support. For design collaboration tools the coordination mechanisms employed are a crucial aspect. To make these mechanisms as flexible as possible, the technical challenge lies in devising an adequate concept for storing the actions that happen during designing. This paper deals with the issue of versioning in computer-supported collaborative design environments. The paper examines the technical and conceptual problems of versioning and discusses possible solutions.