In 1994, Sony, the Japanese manufacturer of consumer electronics, including the WALKMAN brand portable stereos, sued Time Tron Corp., an Austrian company, to prevent Time Tron Corp. from identifying competitive portable cassette players generically as "walkmans."

In its ruling of June 5, 2002, the Supreme Court of Austria held that Sony's trademark WALKMAN had become a common name (i.e. a generic term) for portable stereos and that Sony could not prevent others from using "walkman" for similar goods in Austria.

Unfortunately for Sony, a German dictionary had defined the term "walkman" as a common noun for portable cassette players, and Sony had apparently not taken action to have such definition retracted.

This decision sends a sobering signal to trademark owners that they risk losing their valuable trademark rights based on inaccurate dictionary references and reinforces the need for diligent policing of the same.