the definition for purposes of clarification: grey literature is "...not controlled by commercial publishers, i.e., where publishing is not the primary activity of the producing body". This definition is now widely accepted by the scholarly community. The U.S. Interagency Gray Literature Working Group (IGLWG), in its "Gray Information Functional Plan" of 1995, defined grey literature as "foreign or domestic open source material that usually is available through specialized channels and may not enter normal channels or systems of publication, distribution, bibliographic control, or acquisition by booksellers or subscription agents". Thus grey literature is usually inaccessible through relevant reference tools such as databases and indexes, which rely upon the reporting of subscription agents. Other terms used for this material include: report literature, government publications, policy documents, fugitive literature, non-conventional literature, unpublished literature, non-traditional publications, and ephemeral publications. With the introduction of desktop publishing and the Internet, new terms include: electronic publications, online publications, online resources, open-access research, and digital documents. Though the concept is difficult to define, the term grey literature is an agreed collective term that researchers and information professionals can use to discuss this distinct but disparate group of resources. In 2010, D.J. Farace and J. Schöpfel pointed out that existing definitions of grey literature were predominantly economic, and argued that in a changing research environment, with new channels of scientific communication, grey literature needed a new conceptual framework. They proposed the "Prague definition" as follows: Due to the rapid increase web publishing and access to documents, the focus of grey literature has shifted to quality, intellectual property, curation, and accessibility. Publication types The term grey literature acts as a collective noun to refer to a large number of publications types produced by organizations for various reasons. These include: research and project reports, annual or activity reports, theses, conference proceedings, preprints, working papers, newsletters, technical reports, recommendations and technical standards, patents, technical notes, data and statistics, presentations, field notes, laboratory research books, academic courseware, lecture notes, evaluations, and many more. The international network GreyNet maintains an online listing of document types. Organizations produce grey literature as a means of encapsulating, storing and sharing information for their own use, and for wider distribution. This can take the form of a record of data and information on a site or project (archaeological records, survey data, working papers); sharing information on how and why things occurred (technical reports and specifications, briefings, evaluations,