In the academic world, "gray literature," which is often spelled "grey literature" following the British usage, is a term referring to certain types of publications. Gray literature refers to a wide variety of documents, including technical papers; internal publications by corporate or university research departments; government publications, which are sometimes known as "white papers;" field reports; and more. Although these documents may be of interest to scientists and academics, they are often difficult to obtain because they are neither books nor journals and may therefore not be held by libraries. Gray literature is also often published only in small print runs.
The term "gray literature" began to emerge in the 1970s to meet demand for a phrase to describe the ever-increasing number of publications from organizations which were not primarily publishers, in contrast to what was commonly thought of as academic literature: the mainstream content of academic books and journal articles. These publications contained large amounts of useful data. They were particularly useful because the process of academic publishing often meant that delays were common in publishing research. By contrast, publication of less-formal reports was much quicker, and could be achieved as much as a year or more ahead of publication in academic journals. Those who had access to this type of data enjoyed a useful advantage.
Gray literature had the potential to be a boon to researchers, but it also posed challenges. Not all libraries or researchers had access to this type of literature. Even if they did have access, bibliographic data for reports and publications of this type was often absent or incomplete, meaning that the necessary publications could be hard to locate. A researcher might simply not be aware of the existence of reports relevant to his or her work. This began to change as the 1980s and 1990s saw an increasing awareness of the importance of gray literature, but many of the problems were difficult to overcome.
As a response to these challenges, there have been a number of efforts among the academic community to improve access to gray literature, both in specific fields and in general. Within the field of British archaeology, for instance, the Archaeology Data Service (ADS) maintains a library of unpublished fieldwork reports known as the Grey Literature Library. In the broader academic world, organizations such as the Grey Literature International Steering Committee work to make sure that gray literature producers adhere to certain standards which make their work easier for librarians and researchers to use.