Using grey literature

Grey material comprises pamphlets, unpublished material, discussion and working papers, policy documents, reviews, technical, research or private communications, and other such ephermeral material that falls outside of the traditional definitions of books, periodicals, newpapers, videos, etc., and hence is often not collected systematically, is uncatalogued and difficult to trace.

The European Association for Grey Literature Exploitation established and manages the System of Information on Grey Literature in Europe (SIGLE) database. Its aims are to provide access to such 'grey' or 'fugitive' publications which are either not published or cannot readily be acquired through normal bookselling channels and which are therefore difficult to identify and obtain.

The Research Libraries Group's "Inaccessible Domain" Materials Working Group has identified five material types -- catalogs, clippings, visual resources, architectural records, and documents for the purposes of testing in its project. The chief criteria for selection of items were that they be considered important enough to to warrant access, and that they be commonly found in library collections. The material types apply to all physical formats (printed, visual, and machine-readable).