A more thorough explanation:

A Declaration of Continued Use is a legal document that trademark owners must submit to the U.S. Patent and Trademark Office to maintain their trademark registration. It is also known as a Declaration of Use.

The Declaration of Continued Use is a sworn statement that confirms that the registered trademark is still being used in commerce. The trademark owner must provide a specimen or facsimile of the mark's use as evidence.

The Declaration of Continued Use must be filed every five or six years following registration and the year before the end of every ten-year period after the date of registration. If the trademark owner fails to file the Declaration of Continued Use within the required time, the U.S. Patent and Trademark Office may cancel the registration.

Let's say that a company registered a trademark for their product "XYZ" in 2010. In 2015, they filed a Declaration of Continued Use to confirm that they were still using the trademark in commerce. They filed another Declaration of Continued Use in 2020, and they will need to file another one in 2029 to maintain their trademark registration.

These examples illustrate how trademark owners must regularly confirm that they are still using their registered trademarks to maintain their legal protection.