Following are definitions to assist in determining if the nonmachinable surcharge applies:

• Booklet: A letter-size mailpiece consisting of multiple pages permanently bound along one edge or spine using staples, glue, stitching, or other permanent fastening and open on the other three edges.
• Folded Self-Mailer: A letter-size mailpiece designed to be mailed without an envelope and consisting of one or more sheets of paper that are folded at least once. Multiple sheets may be loose and nested inside one another or may be stapled in the corner.
• Final Fold: When a mailpiece is folded more than once into its final mailing format the final fold is the outermost fold and is usually the last fold.