Reduced rates of Standard Mail® postage are available for eligible
organizations that the United States Postal Service® (USPS®) has authorized
and whose individual mailings meet the specific eligibility rules that apply to
Nonprofit Standard Mail.
The U.S. Congress authorized these reduced rates in 1951 and determined
the categories of organizations eligible for the rates (see 2-2). Subsequent
legislation extended the privileges to other categories and added restrictions
on what material may be mailed at the Nonprofit Standard Mail (nonprofit)