When you’re trying to register a trademark for apparel in the U.S., there are some specific requirements. In my experience, many clients who are starting an apparel brand don’t know these requirements, and it can lead to trouble. The key issue is that in order to protect and register a trademark in the U.S., you need to be able to show that the mark has been used in interstate commerce in connection with the goods in the application. For some kinds of products, simply having the trademark (brand name or logo) appear on the product is good enough. But for…