Data breaches and other security incidents are an emerging challenge in the digital era. The General Data Protection Regulation (GDPR) requires conducting an impact assessment to understand the effects of the breach, and to then notify authorities and affected individuals in certain cases. Communication of this information typically takes place via conventional mediums such as emails and forms on the websites of authorities, and is a manual process. To assist in developing tools to support data breach investigations, and to enable automated systems for assisting with breach assessments and GDPR compliance, we present a machine-readable specification for the representation and documentation of information related to data breaches and their communications. The specification uses current requirements from the GDPR obligations and authoritative guidelines. To represent information, it extends the Data Privacy Vocabulary (DPV) by introducing new concepts required for data breach relevant information.