The 43(B)log discusses a recent Third Circuit opinion on this topic — one that people ask me about all the time. Well, ask Rebecca Tushnet! Her bottom line:
Essentially, the court of appeals thought that the district court had created a near-absolute “house brand” defense independent of the confusion factors, which was inappropriate. The court of appeals recognized that a prominent house brand might allow store brands to “‘get away’ with” a little more similarity than other defendants’ comparable products. But a tiny differentiating label won’t suffice in any event.
Hat tip to Marty Schwimmer.