How does public accessibility affect the status of a printed publication in patent law?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Public accessibility is a crucial factor in determining whether a document qualifies as a printed publication under patent law. According to MPEP 2152.02(b):

“The public accessibility of the material is the key inquiry in determining whether a reference qualifies as a ‘printed publication’ bar under 35 U.S.C. 102(a)(1).”

This means that:

• The material must be accessible to the public or to persons interested and ordinarily skilled in the subject matter.
• There must be no reasonable expectation of secrecy.
• The date of public accessibility is considered the publication date.

For example, a thesis in a university library or a paper presented at a conference may be considered publicly accessible if it’s available to those interested in the field without restriction.