International audience; One of the funded project proposals under DARIAH’s Open Humanities call 2015 was “Open History: Sustainable digital publishing of archival catalogues of twentieth-century history archives”. Based on the experiences of the Collaborative EuropeaN Digital Archival Research Infrastructure (CENDARI) and the European Holocaust Research Infrastructure (EHRI), the main goal of the “Open History” project was to enhance the dialogue between (meta-)data providers and research infrastructures. Integrating archival descriptions – when they were already available – held at a wide variety of twentieth-century history archives (from classic archives to memorial sites, libraries and private archives) into research infrastructures has proven to be a major challenge, which could not be done without some degree of limited to extensive pre-processing or other preparatory work. The “Open History” project organized two workshops and developed two tools: an easily accessible and general article on why the practice of standardization and sharing is important and how this can be achieved; and a model which provides checklists for self-analyses of archival institutions. The text that follows is the article we have developed. It intentionally remains at a general level, without much jargon, so that it can be easily read by those who are non-archivists or non-IT. Hence, we hope it will be easy to understand for both those who are describing the sources at various archives (with or without IT or archival sciences degrees), as well as decision-makers (directors and advisory boards) who wish to understand the benefits of investing in standardization and sharing of data. It is important to note is that this text is a first step, not a static, final result. Not all aspects about standardization and publication of (meta-)data are discussed, nor are updates or feedback mechanisms for annotations and comments discussed. The idea is that this text can be used in full or in part and that it will include further chapters and section updates as time goes by and as other communities begin using it. Some archives will read through much of these and see confirmation of what they have already been implementing; others – especially the smaller institutions, such as private memory institutions – will find this a low-key and hands-on introduction to help them in their efforts.