A more thorough explanation:

A family of marks is a group of trademarks that have a common characteristic that makes them recognizable to consumers as coming from the same source. For example, McDonald's has a family of marks that all begin with "Mc-", such as the Big Mac, McChicken, and McFlurry.

Another example of a family of marks is the "i" prefix used by Apple for products like the iPhone, iPad, and iMac. These marks all share the common characteristic of starting with the letter "i" and being associated with Apple.

The purpose of a family of marks is to create a strong brand identity and make it easier for consumers to recognize and remember a company's products. By using a consistent naming convention, companies can build brand loyalty and increase the value of their trademarks.