How extensive should an interference search be in terms of patent classifications?

An interference search should be comprehensive and not limited to the primary classification of the application. The MPEP 2304.01(a) provides clear guidance on the scope of the search:

“The search for interfering applications must not be limited to only the classes or subgroups in which the application is classified, but must be extended to all classes in which it has been necessary to search in the examination of the application. See MPEP § 1302.08.”

This requirement ensures that examiners conduct a thorough search across all relevant technological areas to identify any potential interfering subject matter, regardless of how it may be classified.

To learn more:

Topics: MPEP 2300 - Interference And Derivation Proceedings, MPEP 2304.01(A) - Interference Search, Patent Law, Patent Procedure
Tags: comprehensive search, Interference Search Scope, mpep 1302.08, Patent Classifications