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Selection Guidelines for Non-National Library of Medicine Resources


The web site of the National Library of Medicine's (NLM) Division of Specialized Information Services (SIS) is designed to help you find appropriate and trustworthy health information. To do this, we provide access to information produced by the National Library of Medicine, the National Institutes of Health, and other US government agencies. This information may serve professionals or consumers.

The SIS web site also contains pages that link to non-US government Web sites. To ensure access to reliable information, the following guidelines are used for linking to non-NLM sites.


  • The goals of the Web site and sponsoring organizations are clearly identified.
  • The organization's mission relates to the goals of the site.

Authority, Credibility, and Affiliation

  • Emphasis is on U.S. federal and state government resources, major national (scientific societies, professional organizations, etc.), and international organizations (World Health Organization, etc.).
  • Sponsorship of the site is clear. The credentials or qualifications of the sponsors, writers, or producers are provided.
  • Sites produced by individuals are not included unless there is no other source of the information. The author's name, title, affiliation, and credentials must be provided.
  • Focus is on non-commercial sites. If a commercial site is linked to it the following conditions need to be present:
    • Site makes an obvious distinction between material created for advertising and material created for information.
    • Most content must be available at no charge or be clearly labeled if charges apply.
    • The site's content or presentation should not cause a reasonable user to conclude that products or services are endorsed.

Content, Coverage, and Currency

  • Sites are evaluated to make sure that high-quality information is provided, and that the information is from original sources which are listed on the web site.
  • The source for the contents of the Web page(s) and the identification of those responsible for maintaining the Web site (webmaster, organization, creator of the content) are clear.
  • Information on the site is unique and not readily available elsewhere. There is a minimum of duplication and overlap between resources. For example: unique images or a glossary that are not found at other web sites.
  • Information about when a page was created, revised, or last updated should be provided.

Point of View

  • No conflicts of interest are apparent; example: advertising by a sponsor.

Intended Audience

  • Intended audience is clear and materials are written at a level appropriate for that audience.
  • The primary purpose of the Web page is educational.

Access, Navigation, and Availability

  • Site is consistently available and loads without problems.
  • Links on the site are functional most of the time.
  • Site is well-organized and users can move around the site easily.
  • Registration, an account, or password is not required to access site information. If registration is requested, how that data is used is clearly stated.


  • An English language version of the Web site is available
  • Certain pages within the SIS site provide information for non-English speaking populations. Because the aim of those pages is to provide information in a population's native language there are links to sites that may have no English equivalents.


  • Reference to an external Internet resource on this site does not constitute a recommendation or endorsement by the National Library of Medicine of the services or views described in that resource.
  • PDF documents can be viewed with the free Adobe® Reader.

Last Reviewed: September 11, 2018