operating system | Alexander Graham Bell | Super Nintendo Entertainment System | Nintendo Entertainment System | Bell Labs | Android (operating system) | Taco Bell | Global Positioning System | Joshua Bell | Solar System | X Window System | Korean Broadcasting System | Bell Canada | System of a Down | Domain Name System | Seoul Broadcasting System | North Carolina Community College System | Mutual Broadcasting System | Liberty Bell | Bulletin board system | Bell X-1 | Bell | system | Turner Broadcasting System | Program and System Information Protocol | Geographic information system | For Whom the Bell Tolls | Ubuntu (operating system) | Tokyo Broadcasting System | Federal Reserve System |
While this data was originally maintained by telephone companies, the breakup of the Bell System in the 1980s and the introduction of toll-free number portability in 1993 required an independent operator maintain the SMS/800 database.