Reports by the Congressional Research Service, usually referred to as CRS Reports, are the encyclopedic research reports written to clearly define issues in a legislative context. Over 700 new CRS reports are produced each year; almost 4,000 exist. The types of CRS reports include Issue Briefs (IB), Research Memos (RM), and Reports, which appear in both Short (RS) and Long (RL) formats.
Other than a passing generic reference to “reports” in its statutory charter, CRS has no mandate for these products. They are created in the context of the overall mission of CRS to provide research support to Congress.
The Library of Congress, the home of CRS, had experimented during the 1940s with unrestricted publication Public Affairs Bulletins, which were produced by staff of the Legislative Reference Service, and devoted to various public policy issues. They were promoted by Archibald MacLeish, the Librarian of Congress, and, among other topics, addressed timely policy issues, such as American national defense. About 100 Public Affairs Bulletins were generated  before congressional appropriators ended their production in 1951.
When the Congressional Research Service Review was launched in 1980, it continued for a little more than a decade before congressional appropriators, once again, invoked fiscal closure with the last issue published v. 13 #9 (Sept. 1992). The Review, which was published ten times a year and available to the public by subscription, offered original analytical articles, summaries highlighting CRS research products, and other kinds of assistance to the congressional community.
CRS reports may contain excerpts of material from copyrighted sources. However, this content will be "appropriately credited". Thus, persons seeking public domain content in CRS reports can avoid infringing copyright by paying attention to the internal citations.
The New York Times has written,
However, in a passage analyzing its own liability under United States copyright law, the CRS has written that its works may contain copyrighted information, but that these excerpts are always "appropriately credited":
CRS adds that:
CRS written work products fall into three major categories:(1) Congressionally Distributed Products Providing Research and Analysis on Legislative Issues, (2) Responses to Individual Members and Committees, and (3) Legislative Summaries, Digests, and Compilations.
Congressionally Distributed Products Providing Research and Analysis on Legislative Issues itself is broken into two subcategories: Reports for Congress and Congressional Distribution Memoranda.
Reports for Congress: CRS often prepares reports for Congress, analyses, or studies on specific policy issues of legislative interest. These reports clearly define issues in legislative contexts. Analysts define and explain technical terms and concepts, frame the issues in understandable and timely contexts, and provide appropriate, accurate, and valid quantitative data. The content of the report is summarized on its first page. These reports may be updated as events occur, or archived when they no longer reflect the current legislative agenda but can provide background and historical context.
Congressional Distribution Memoranda: Similar to the reports, memoranda are prepared when the interest of a relatively small number of congressional readers is anticipated or when an issue is sufficiently transient that CRS deems it inappropriate to include it in its list of products. Memoranda can be recast as a report if it becomes important to a larger congressional audience.
Responses to Individual Members and Committees: CRS staff provide custom services for Members and committees and their staff, tailored to address specific questions, and usually in a memorandum format. Written documents include Confidential Memoranda, Email Responses, and Briefing Books.
Confidential Memoranda: Confidential memoranda are prepared to meet a specific congressional request and are often designed for a congressional reader with a high level of expertise in a given topic. These memoranda are prepared for the use of the requester and are not distributed by CRS to a larger audience unless the requester gives permission.
Email Responses: Email responses to request for information can range from providing a statistic or a name to a short briefing to an interactive discussion on a variety of issues.
Briefing Books: Prepared for use by congressional delegations traveling abroad, these books are collections of material that support the specific purposes of a congressional trip. Briefing books can include a variety of materials, such as maps, selected products, and brief tailored written work, all of which contain background and current issues regarding U.S. relations with specific countries on the trip as well as questions Members may ask when meeting with government or other officials.
Legislative Summaries, Digests, and Compilations: Since 1935, the Legislative Analysis and Information Section (formerly the "Bill Digest" section) of CRS has had the statutory responsibility for preparation of authoritative, objective, nonpartisan summaries of introduced public bills and resolutions and the maintenance of historical legislative information. Detailed revised summaries are written to reflect changes made in the course of the legislative process. This CRS office also prepares titles, bill relationships, subject terms, and Congressional Record citations for debates, full text of measures, and Member introductory remarks.
Many but not all CRS reports can be obtained through the official US government website crsreports.congress.gov, older CRS reports versions may be accessed from community supported sources.
Some CRS reports are available to the public through the official US Congress website crsreports.congress.gov, this website was released to the public on September 18 2018. Previously CRS reports were confidential, while not classified they were exempt from FOIA due to Congressional privilege and therefore not readily accessible nor was their authenticity easily verifiable .