Insights

Patent claims must be clear and definite, as they set the boundaries of the patentee’s rights. Occasionally, however, claim language contains errors, such as typographical mistakes or incorrect numbering. Courts possess very limited authority to correct such errors. The United States Court of Appeals for the Federal Circuit has emphasized that judicial correction is appropriate only in rare circumstances, where (1) the error is evident from the face of the patent, and (2) the proposed correction is the sole reasonable interpretation in view of the claim language, specification, and prosecution history. See Group One, Ltd. v. Hallmark Cards, Inc., 407 F.3d 1297, 1303 (Fed. Cir. 2005) and Novo Indus., L.P. v. Micro Molds Corp., 350 F.3d 1348, 1357 (Fed. Cir. 2003).