Customer Support Ruling
UPDATED June 2014
This CSR provides a definition of “libraries” as stated in the Domestic Mail Manual.
The libraries referred to in Domestic Mail Manual (DMM) 273* are public libraries. A public library typically is one which is supported by public funds and whose services are freely available to everyone. The libraries mentioned in those regulations may also be school, college, or university libraries when the reference materials are available to the public even though on site reference is required.
*See also DMM 173.
Headquarters, US Postal Service
Washington DC 20260-3436