Given the rotary dialing technology in use at the time, the North American Numbering Plan Administrator wanted to keep the number of "clicks" to a minimum for large cities.
Within the United States and Canada, Neustar administrates the North American Numbering Plan, the authoritative directories that manage virtually all telephone area codes and numbers, and enables the routing of calls among thousands of competing communications service providers (CSPs).
In the North American Numbering Plan, a RespOrg (a contraction for responsible organization) is a company which maintains the registration for individual toll-free telephone numbers in the distributed Service Management System/800 database.
American | American Civil War | American Broadcasting Company | American football | North Carolina | North America | African American | American Idol | American Revolutionary War | North Rhine-Westphalia | American Revolution | North Korea | North Yorkshire | University of North Carolina at Chapel Hill | American Association for the Advancement of Science | American Red Cross | North Island | North Sea | North Africa | American Library Association | American Museum of Natural History | North Dakota | North | American Express | American Academy of Arts and Sciences | American League | American Association | American Heart Association | Raleigh, North Carolina | Chapel Hill, North Carolina |
Canadian numbers are an exception as they are drawn from the same SMS/800 pool as other North American Numbering Plan countries, although the arbitrary distinctions between Local Exchange Carrier/Interexchange carrier, intrastate/interstate and the LATA structure are artificial US regulatory constructs which do not have direct parallels in Canada or any other nation.