Public policy and practice, and policy research, relies on diverse forms and types of information and communication, both traditional publications and a myriad of other documents and resources including reports, briefings, legislation, discussion papers, submissions and evaluations and much more. This is sometimes referred to as ‘grey literature’, a collective term for the wide range of publications produced and published directly by organisations, either in print or digitally, outside of the commercial or scholarly publishing industry. In the digital era grey literature has proliferated, and has become a key tool in influencing public debate and in providing an evidence-base for public policy and practice. Despite its ubiquity and influence, grey literature's role is often overlooked as a publishing phenomenon, ignored both in scholarly research on media and communications and in the debate on the changing nature of open access and academic publishing. This paper looks at the production of grey literature for public policy and practice where the changes enabled by computers and the internet are causing a hidden revolution in the dissemination of knowledge and evidence. It explores the production, dissemination and management of publications by organisations, their nature, purpose and value, and investigates the benefits and the challenges of publishing outside of the commercial or scholarly publishing enterprises. The paper provides estimates of the economic value of grey literature based on online surveys and valuations and considers the costs and benefits of self-publishing by organisations which provides both a dynamic, flexible and responsive publishing system and one in which link rot, duplication and highly varying standards abound. The findings are part of a broader research project looking at role and value of grey literature for policy and practice including consumption, production and collection. It will be of interest to a wide range of policy makers and practitioners as well as academics working in media and communications, public administration and library and information management.