| 1 | SIT | SITA | IATA: XS | | ICAO1 |
| 2 | SITAC | Calais Opale Bus | City: Calais | F | TRAFFIC |
| 3 | SITB | SITSA | | | SCAC4 |
| 4 | SITB | Sihltalbahn | | CH | TRAFFIC |
| 5 | SITC | SKINNER TRANSFER CORP | | | SCAC1 |
| 6 | SITC | SKINNER TRANSFER CORP | | | SCAC4 |
| 7 | SITD | SIMBOL INTERNATIONAL TRADE | | | SCAC4 |
| 8 | SITFA | Societa Italiana Trasporti Ferroviari Autoveicoli spa | | I | TRAFFIC |
| 9 | SITFA | SITFA S.p.A. (TO) | | IT | VKM |
| 10 | SITI | SIMON TRUCKING, INC | | | SCAC1 |
| 11 | SITL | SAHAULI TRANSPORT LTD | | | SCAC4 |
| 12 | SITM | SITTON MOTOR LINES INC | | | SCAC4 |
| 13 | SITO | SITSA | | | SCAC4 |
| 14 | SITP | SILICA TRANSPORT INC | | | SCAC4 |
| 15 | SITQ | SITRA | | | SCAC4 |
| 16 | SITR | SEVENSKI, STEPHEN TRUCKING INC | | | SCAC4 |
| 17 | SITS | SIDNEY TRUCK & STORAGE, INC | | | SCAC1 |
| 18 | SITT | SPIRIT INTERNATIONAL TRANSPORT INC | | | SCAC4 |
| 19 | SITU | SITC CONTAINER LINES CO LTD | | PRC | BIC |
| 20 | SITU | SITC CONTAINER LINES CO LTD | | | SCAC4 |
| 21 | SITV | SONA INTER TRANSPORT INC | | | SCAC4 |
| 22 | SITW | SCHISLER TRUCKING | | | SCAC4 |
| 23 | SITWN | Siemens AG Transformatorenwerk Nürnberg | | DE | VKM |
| 24 | SITX | Sherritt International Corp. | added 4/1997; 7/2000-7/2005; eliminated 1/2007 | | NAKINA |
| 25 | SITX | Sherritt International Corp. | added 4/97; 7/2000 | | NRHS |
| 26 | SITX | SHERRITT INTERNATIONAL CORPORATION | | | PWRC |
| 27 | SITX | Sherritt International Corporation | | | RSRV |
| 28 | SITY | SICC TRUCKING | | | SCAC4 |
| 29 | SITZ | SITTON MOTOR LINES INC | | | SCAC4 |
