Preamble Language Presumed To Provide Context, Not Impose Limitations

Addressing the rules of claim construction pertaining to preambles and preferred embodiments, the U.S. Court of Appeals for the Federal Circuit vacated the district court's summary judgment of non-infringement. Symantec Corp. v. Computer Assoc. Int'l, Inc. et al, Case Nos. 07-1201, -1239 (Fed. Cir., April 11, 2008) (Dyk, J.).

Symantec Corporation appealed from the district court's summary judgment that Computer Associates Int'l, Inc. did not infringe U.S. Patent No. 5,319,776 (the '776 patent). Symantec argued the district court erred in its claim construction on two grounds: reading a term from the preamble as a claim limitation and limiting the scope of a claim term to the preferred embodiment.