A more thorough explanation:

A collective trademark is a type of trademark used by a group or association to identify their products or services or to show membership in the group. It is similar to a regular trademark, which is used by a company to distinguish its products from others. To be protected under federal law, a trademark must be distinctive, affixed to a product that is sold, and registered with the U.S. Patent and Trademark Office.

Examples of collective trademarks include "Realtor" and "American Peanut Farmers." These marks are used by groups to identify their members and products. For example, the "Realtor" mark is used by members of the National Association of Realtors to show that they are licensed real estate professionals. The "American Peanut Farmers" mark is used by a group of peanut farmers to show that their products are grown in the United States.