Absolute-bar rule

{
  "id": "MLC-T-LAW-000278",
  "term": "Absolute-bar rule",
  "field": "Law",
  "definition": "A rule the Federal Circuit adopted in the Festo litigation holding that a narrowing amendment made to a patent claim for a reason related to patentability completely bars the patentee from invoking the doctrine of equivalents for the amended claim element. The Supreme Court rejected it in 2002 and substituted a rebuttable presumption that the patentee surrendered the territory between the original and amended claim. The patentee may overcome the presumption by showing the equivalent was unforeseeable or tangential to the amendment.",
  "url": "https://mlchart.com/terminology/law/absolute-bar-rule/"
}