By Kevin Wagner and Theodore Budd (December 19, 2017, 11:30 AM EST) -- It has long been clear that the patentee bears the ultimate burden of pleading and proving compliance with Section 287(a)'s marking requirement if they hope to recover presuit damages for patent infringement. Maxwell v. Baker Inc, 86 F.3d 1098, 1111 (Fed. Cir. 1996). But who bears the initial burden of showing there were patented products for which marking was required? The Federal Circuit has left this question unanswered, and district courts have struggled to reach a consensus. This all changed with the Dec. 7, 2017, decision in Arctic Cat Inc. v. Bombardier Recreational Products Inc., where the Federal Circuit held that "an alleged infringer who challenges the patentee's compliance with § 287 bears an initial burden of production to articulate the products it believes are unmarked 'patented articles' subject to § 287." Then, "the patentee bears the burden to prove the products identified do not practice the patented invention." In practice, this decision means:...