What are defensive publications in patent examination?

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.

Defensive publications, as mentioned in MPEP 901.06(d), are documents published to establish prior art without pursuing patent protection. The MPEP states:

“Defensive Publications, which are patent applications voluntarily published without examination, are included in the search files.”

These publications serve as a defensive strategy to prevent others from patenting similar inventions. They are considered prior art and are included in patent examiners’ search files for reference during the examination process.