What is the difference between a Defensive Publication and a patent application publication?

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.

A Defensive Publication is distinct from a patent application publication in several ways:

• It is not a patent or an application publication under 35 U.S.C. 122(b).
• It is considered a publication for prior art purposes.
• It becomes prior art only as of its publication date.
• The applicant waives rights to an enforceable patent when opting for a Defensive Publication.

The MPEP explicitly states: A defensive publication is not a patent or an application publication under 35 U.S.C. 122(b); it is a publication. Therefore, it is prior art only as of its publication date.