In order to preserve the accessibility for the earlier user of the trademark to expand and enter into the related fields, the earlier user undoubtedly has the right to retain his “natural expansion field” which allows him to use his trademark for more types of goods when possible. When the business classes of the earlier user of the trademark become more diverse, it will be more possible for the earlier user to fill the gap. According to the goods or services on which the disputed trademark is designated, the “nutritional supplements” specified by the disputed trademark are similar to the dairy goods which can nourish and improve one’s health. Since the “nutritional supplements” may be functionally interchangeable with the dairy goods specified by the disputed trademark, they should be of the same nature or interchangeable to some extent. As a result, although the plaintiff expands his business from the dairy market to the market of “nutritional supplements,” the act is not inconsistent with the consumers’ perceptions of market expansion.

natural expansion field、the possibility to fill the market gap