Goods and services covered by a trademark are categorized into classes depending on the nature of the goods and services. There are 45 different trademark classes. Classes 1 -34 cover various types of goods and classes 35-45 cover various types of services.
The easiest way to determine what class your goods/services fall in is to search the Trademark ID Manual. Below is a screenshot of a search for “t-shirts” in the Trademark ID Manual. You can see that “T-shirts” is listed as an acceptable identification and is listed in Class 25. If you are having trouble finding an accurate description in the Trademark ID Manual for your goods/services, try describing the goods/services in a different way.
It is possible to use a free-form description of your goods/services if you can’t find an accurate description in the Trademark ID Manual, but the government charges an additional $100 per class if you use a free-form description. Using a free form description requires using a different application type. If you have a multi-class application and one class uses a description from the Trademark ID Manual and the other class uses a free-form description, the additional $100/class government fee will apply to both classes.