A more thorough explanation:

A preliminary amendment is a modification made to a patent application before the U.S. Patent and Trademark Office issues an office action. It is usually done to narrow or eliminate some claims in response to an examiner's rejection.

• John filed a preliminary amendment to his patent application to address the examiner's concerns about the scope of his claims.
• Mary's preliminary amendment eliminated some of the claims in her patent application to make it more focused and easier to examine.

These examples illustrate how a preliminary amendment can be used to address issues raised by the patent examiner and improve the chances of the application being approved.