We created Customer Support Rulings (CSRs) to help Postal Service employees and customers use the information in Mailing Standards of the United States Postal Service,
Domestic Mail Manual (DMM). The CSRs provide examples of specific mailpieces and an analysis of how our mailing standards are applied.
We publish CSRs when needed; new CSRs are announced in DMM Advisory. We delete or consolidate CSRs as mailing standards change. Below is the complete list of active CSRs.