In patent applications, the distinction between essential and nonessential material is important for incorporation by reference: Essential material is defined in 37 CFR 1.57(d) as material necessary to meet the requirements of 35 U.S.C. 112(a), (b), or (f). It can only be incorporated by reference to a U.S. patent or U.S. patent application publication. Nonessential…

To properly incorporate material by reference in a patent application: Use the root words ‘incorporate’ and ‘reference’ (e.g., ‘incorporate by reference’) to express a clear intent to incorporate. Clearly identify the referenced patent, application, or publication. For essential material, only incorporate by reference to a U.S. patent or U.S. patent application publication. For nonessential material,…