The United States Postal Service® (USPS®) published a notice in the August 23, 2010 Federal Register regarding proposed changes to mail preparation requirements for flat size mail destined to Flat Sequencing System (FSS) ZIP codes. These preparation changes would be optional for mailers, and would be made effective on January 2, 2011.
The Flats Sequencing System is part of the USPS strategic plan to increase mail processing efficiency and reduce costs. These pieces of equipment sort flat size mail into delivery sequence, so that less time is spent by mail carriers manually sorting flat size mail into the sequence in which they deliver mail on their routes. The optional preparation changes are for Standard Mail, Periodicals, and Package Services Bound Printed Matter (PSVC BPM) flats.
Look for the next release of Presort to support FSS as well as additional details in the Release Notes.