—"a product feature is functional... if it is essential to the use or purpose of the article or if it affects the cost or quality of the article."

A mark has secondary meaning if "in the minds of public, the primary significance of a product feature or term is to identify the source of the product rather than the product itself."

"[A] manufacturer or distributor [who][(1)] intentionally induces another to infringe a trademark, or...[(2)] continues to supply its product to one whom it knows or has reason to know is engaging in trademark infringement,... is contributorially responsible for any harm done as a result of the deceit."

—the Court said that contributory trademark liability is applicable if defendant (1) intentionally induces another to infringe on a trademark or (2) continues to supply a product knowing that the recipient is using the product to engage in trademark infringement.

Determining the weight and credibility of the evidence is the special province of the trier of fact, and, "unless an appellate court is left with the definite and firm conviction that a mistake has been committed, it must accept the trial court's findings."

The Supreme Court has determined that liability can extend "beyond those who actually mislabel goods with the mark of another."