Magistrate Judge Leung considered this question in Stratasys, Inc. v. Microboards Technology, LLC, Case No. 13-cv-3228. In the case, Stratasys claims that the H-Series 3D printer sold by Microboards Technology (“Afinia”) infringes various patents. Stratasys provided a claim chart with an annotated picture demonstrating how the H-Series printer allegedly infringes. Stratasys did not identify specific portions of source code in its claim chart. 

Form 4 in the Local Rules for the District of Minnesota requires the patent holder to submit a claim chart that identifies: “(1) which claim(s) of its patent(s) it alleges are being infringed; (2) which specific products or methods of defendant’s it alleges literally infringe each claim; and (3) where each element of each claim listed in (1) is found in each product or method listed in (2), including the basis for each contention that the element is present.” The Pretrial Scheduling Order adopted this language. 

Afinia argued that the Stratasys claim chart was insufficient because Stratasys did not identify specific source code. Magistrate Judge Leung disagreed. Judge Leung explained that “the purpose of a claim chart is to set forth a party’s infringement contentions with reasonable particularity so that the parties can focus and advance discovery.” June 23, 2015, Memorandum Opinion and Order, p. 4. Judge Leung found Stratasys’s claim chart sufficient because the claim chart “need only provide Afinia reasonable notice of Stratasys’s theory of infringement, not the specific lines of code that infringe.” Id. at 5 (emphasis in original).