Windowbook--United States Postal Service® (USPS®) published the final regulations for folded self-mailers (FSM's) and other unenveloped pieces in the December 1, 2011 Federal Register. These final rules are based on the proposed regulations published in an earlier Federal Register on August 15, 2011. The USPS renamed pieces designed to carry discs and expands the standards that apply to tabs to include folded self-mailers (FSM's). These new rules do not apply to cards, envelopes, booklet style letters or mailpieces designed to carry discs. Read more!