A more thorough explanation:

A Section 15 affidavit is a sworn statement made by the owner of a registered trademark. It is submitted after five years of registration and confirms that the mark has been in continuous use in commerce for at least five consecutive years since registration. The affidavit also states that the mark has not become generic, there has been no final adverse decision to ownership in the mark, and there is no pending proceeding in the U.S. Patent and Trademark Office or courts involving the mark.

The Section 15 affidavit entitles the mark to immunity from some legal challenges under § 15 of the Lanham Act.

For example, if a company registered a trademark for their product and has been using it for five years without any legal issues, they can submit a Section 15 affidavit to protect their trademark from future legal challenges.

Another example is if a company registered a trademark for their service and has been using it for five years without any legal issues, they can submit a Section 15 affidavit to protect their trademark from future legal challenges.

These examples illustrate how a Section 15 affidavit can help protect a registered trademark from legal challenges after it has been in continuous use for five years.