The German federal government has quietly taken an extremely significant step: hidden amongst the technical specifications of the Deutschland-Stack – the rules that will govern the sovereign digital infrastructure supporting public administration at all levels of government, from federal ministries to local council offices – there is a short but highly significant line. Under the technological pillar “Semantic technologies and real-time analysis”, the document mandates the use of just two document formats: ODF and PDF/UA. That is all. Two open, vendor-neutral formats, defined by international standardisation bodies. OOXML, Microsoft’s closed, proprietary format, is not on the list. What is the Deutschland-Stack? The Deutschland-Stack is the German federal government’s project for a sovereign, interoperable digital infrastructure that complies with European standards. It is neither a pilot project nor a policy discussion paper, but the result of a coordinated decision between the Digital Minister, the Federal Chancellery and the Chancellor, backed by the coalition agreement. The document sets out the standards that will govern how all federal public administrations, at all levels, build, procure and manage their digital systems, and envisages concrete implementation by 2028. It is worth reading its architectural principles carefully. “Made in the EU first.” Reduction of lock-in effects.