What is the significance of canceled matter in U.S. patent files?

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.

Canceled matter in U.S. patent files has specific implications for prior art considerations:

• Canceled matter in the application file of a U.S. patent or U.S. application publication is not considered a proper reference as of the filing date under 35 U.S.C. 102(a)(2) or pre-AIA 35 U.S.C. 102(e).
• However, canceled matter can be used as prior art as of the patent or publication date under 35 U.S.C. 102(a)(1) or pre-AIA 35 U.S.C. 102(a).

As stated in MPEP 901.01: “Canceled matter in the application file of a U.S. patent or U.S. application publication is not a proper reference as of the filing date under 35 U.S.C. 102(a)(2) or pre-AIA 35 U.S.C. 102(e).” This means that canceled content cannot be used to establish an earlier prior art date based on the filing date of the application.