Trademark registration is the best form of protection available to secure the trade name and brand identity of a business. Trademark attorney services in San Diego, CA. Start your trademark registration with Cohn Legal, PLLC.Protect your brand today! The trademark owner's name and address. How to Register a Trademark for Your San Diego Business. To register a trademark, you first want to make sure your trademark is unique. Trademarks are broken down into classes of either goods of services. When applying for a mark you must select at least one class of goods or services. Registering a trademark, or service mark, is an important part of any marketing strategy of any San Diego business. Some business owners prefer to file trademark on their own, to save costs in attorney's fees.