37 CFR 41.203 : Patents, Trademarks, And Copyrights (Section 2.11 To Chapter V) — United States Patent And Trademark Office, Department Of Commerce (Parts 1 - 199) (Section 2.11 To Parts 151-199) — Unknown Title (Parts 2 - 90) (Section 2.11 To Section 90.3) — Practice Before The Patent Trial And Appeal Board (Section 41.1 To Section 41.208) — Patent Interferences (Section 41.200 To Section 41.208) — Declaration.

(a) Interfering subject matter. An interference exists if the subject matter of a claim of one party would, if prior art, have anticipated or rendered obvious the subject matter of a claim of the opposing party and vice versa.

(b) Notice of declaration. An administrative patent judge declares the patent interference on behalf of the Director. A notice declaring an interference identifies:

(1) The interfering subject matter;

(2) The involved applications, patents, and claims;

(3) The accorded benefit for each count; and

(4) The claims corresponding to each count.

(c) Redeclaration. An administrative patent judge may redeclare a patent interference on behalf of the Director to change the declaration made under paragraph (b) of this section.

(d) A party may suggest the addition of a patent or application to the interference or the declaration of an additional interference. The suggestion should make the showings required under § 41.202(a) of this part.