Which type of mark is used to signify membership in a group or association?

A collective mark is specifically designed to indicate membership in a group or association. This type of mark allows members of a specific organization to identify their goods or services as originating from that group, thereby providing an indication of membership and affiliation. For example, a collective mark can be used by members of a trade association to show that their products or services meet the standards and practices of that group.

In contrast, trademarks are used to identify and distinguish the goods of one company from those of others, while service marks serve a similar purpose but for services instead of goods. Certification marks, on the other hand, are used to signify that goods or services meet certain standards and are not specific to a group of members; they can be owned by an organization that sets the standards but can be used by anyone who meets those standards. Thus, the defining characteristic of a collective mark is its role in denoting group membership, making it the correct choice in this context.