To make the desired change, you write and run an agent that runs a formula. When you write the formula, you specify the documents that you want Lotus Notes/Domino to scan to make the change. By adding a SELECT statement to the formula, you can further limit the documents that Lotus Notes/Domino looks at when you run the agent.
SELECT Categories != "Unsigned Contracts";
FIELD Status := "Closed";
SELECT @IsAvailable(Year) & Year > 1995
SELECT !@IsAvailable(Year) | Year > 1995