USPS Mailing Standards

CMU collaborated with the US Postal Service to improve the Domestic Mail Manual, a 1500-page collection of standards that governs the flow of mail within the United States.

As part of a small team of graduate and PhD students, I spent two years working on the final document in the series, the DMM 300.

USPS Domestic Mail Manual

The Problem

The Domestic Mail Manual (DMM) was first redesigned over a decade ago by the Postal Service with a mandate to reduce redundancy within the document. The redesign accomplished that, but introduced a new problem. By dividing the rules into discrete categories with no overlap, readers were forced to flip back and forth more often between multiple sections.

The disorientation within the new structure meant that users were never quite sure they had all the information they needed to complete a mailing.

Our Approach

The first few months of this project were spent on user research. We talked with postal employees and large mailers around the country in order to understand how they actually completed their mailings.

Most customers mail the same sort of things week in and week out. That means they only use a fraction of the information inside the book. We realized that focusing on these "user pathways" was the key to the redesign.


The new DMM uses "shape of mailpiece" as its central organizing principle. We regrouped the rules into sections for letters, flats (large letters), and parcels. Appropriate information is repeated across multiple classes of mail so that, from any particular user's point of view, their rules are all in once place.