Trademarks are highly specific, in the sense that your mark will only apply to the type or "class" of goods or services for which you seek protection. Third parties will be able to use your mark for products or services that differ from yours. For example, the word "Delta" can be a trademark of both a dairy company and an airline.   The trademark application should also specify the goods and/or services that your trademark will cover. Products and services are divided into 'classes'.   Classes are product or service categories into which trademarks are classified. Goods and services are divided internationally into 45 categories, trade classes. In positions 1-35 we find the goods, while from 36-45 the services are categorized. Depending on the categories a mark covers, it is filed and registered in the corresponding trade classes, whether it concerns a general company mark or a specific product mark.   The process of classifying the products/services that will distinguish the mark into classes as well as the wording thereof is of decisive importance for the protection of a mark and needs attention and consultation. It is also important to foresee your future activities, as no additions are allowed after the application for trademark registration has been filed.   Therefore, if you decide in the future to expand to another class that you did not foresee when filing, you will need to file a new mark for that new class.