The term 'special-interest, e.g.' can be summarized as a NICHE, which is a five letter word. A NICHE is a specialized market or area of interest that is often targeted by businesses and organizations. It is typically a smaller, more focused segment of the overall market, and it is often used to identify and target specific groups of people who have similar interests or needs. NICHE markets are often used to create products or services that cater to a specific group of people, and they can be very profitable for businesses.