A more thorough explanation:

A blackout period is a term used in trademarks. It refers to the time between the approval of an intent-to-use application by the examining attorney for publication in the Official Gazette and the issuance of a notice of allowance after publication. During this period, the applicant is not allowed to make any substantive amendment to the application or file a statement of use.

Let's say a company has filed an intent-to-use application for a trademark. The examining attorney approves the application for publication in the Official Gazette. However, before the notice of allowance is issued, there is a blackout period during which the applicant cannot make any changes to the application or file a statement of use.

During the blackout period, the applicant cannot add or remove any goods or services from the application. They also cannot change the description of the goods or services or the trademark itself. The purpose of the blackout period is to ensure that the trademark application process is fair and transparent for all applicants.