Lentz Engineering designed desiccant free HVAC systems using outside air for schools and other public and commercial buildings. Lentz marketed its systems under its REGENERATIVE DUAL DUCT mark. The Trademark Office Examining Attorney rejected its application based on an assertion that the mark merely described Lentz Engineering’s services. After Attorney Sokol appealed Examining Attorney’s Final Refusal to the Trademark Trial & Appeal Board (TTAB), the Office issued U.S. Registration No. 3,170,524 for engineering design services, namely designing desiccant-free heating, ventilation and air conditioning systems using 100% outside air for others.