GPO corresponds to the Monthly Catalog and includes citations from the annual Periodicals Supplement and the United States Congressional Serial Set Supplement.

The Monthly Catalog contains approximately 50 percent of the published government documents. Many administrative documents and reports are excluded, as are items classified for reasons of national security. Some of the documents are for official use only, but 60 to 70 percent are available for purchase directly from the Superintendent of Documents.

GPO includes works such as, monographs, serials, maps and some audiovisuals. Database coverage includes topics such as finance, business, demographics, agriculture, medicine, and public health. In most cases, the subject area can be inferred from the self-descriptive titles and from the nature of the issuing agencies. The records also contain subject descriptors, taken from the Library of Congress Subject Headings, and identifiers, taken primarily from the National Agricultural Library and National Library of Medicine thesauri.