A national qualifications framework (NQF) is an instrument used to classify a country's qualifications at different levels. Each level is defined by a set of learning outcomes expected at that level. NQFs can be useful tools in education and training reforms and are vital reference points for lifelong learning and comparing qualifications across borders. The "Global Inventory of Regional and National Qualifications frameworks 2019, Volume I: Thematic chapters" comprises six thematic chapters, charting developments in national and regional qualifications frameworks worldwide. It shows the extent to which countries see NQFs as instruments for reforming their qualifications systems to improve transparency, relevance and quality, as well as widening access and opening up pathways to learning opportunities. This fourth edition (the first three editions appeared in 2013, 2015 and 2017) of the "Global Inventory of Regional and National Qualifications Frameworks" arrives at a crucial moment in the relatively short history of qualifications frameworks as tools within the wider reforms of education and training systems. Numbers of frameworks, national and regional, remain stable, while implementation of most frameworks has deepened and widened since 2017. At the same time, frameworks are evolving in a context of ever-faster technological, social and economic change. Much of this change has a direct bearing on the purposes and function of frameworks, notably the search for systems which compare skills and qualifications internationally, the emergence of digital credentials, and the development of methods and tools to recognise the skills of migrants and refugees, especially where those skills are undocumented or not formally certificated. [For Volume II: National and Regional Cases, see ED604742.]