While issued patents and published patent applications make up a substantial majority of all prior art references, the USPTO can still issue a number of rejections based on non-patent literature (NPL). Non-Patent Literature is any document and/or publication that is not an issued patent or published patent application.

Some examples of non-patent literature include:

  • Technical manuals;
  • Conference presentations;
  • Posters;
  • Journal articles;
  • Facebook posts;
  • Blog articles; or
  • Book

It is important to remember that prior art is anything that has been published and publicly accessible in any language anywhere in the world.