| 1 | GSO | Global Flight Solutions Ltd | Callsign: Sky Walker, | GB | AVCODES |
| 2 | GSOA | GREAT SOUTHERN COACHES OF | | | SCAC4 |
| 3 | GSOC | GRIST OIL COMPANY | | | SCAC4 |
| 4 | GSOF | GRAEBEL/SOUTH FLORIDA MOVERS INC | | | SCAC4 |
| 5 | GSOK | GREENBUSH LOGISTICS INCORPORATED | | | SCAC4 |
| 6 | GSOM | GREAT SOUTHERN MOTOR CARGO INC | | | SCAC4 |
| 7 | GSON | GOLDEN STATE OVERNIGHT | | | SCAC4 |
| 8 | GSOP | G & S OIL PRODUCTS INC | | | SCAC4 |
| 9 | GSOR | Wabash & Ohio R.R. | added 1/1995 | | NAKINA |
| 10 | GSOR | Indiana Hi-Rail Corp. | added 7/1995; eliminated 7/1998; 7/2000-7/2005 | | NAKINA |
| 11 | GSOR | Indiana Hi-Rail Corp. | added 4/1986; 1/1994; eliminated 1/1995 | | NAKINA |
| 12 | GSOR | Indiana Hi-Rail Corp. | added 4/86; 1/94; eliminated 1/95 | | NRHS |
| 13 | GSOR | Wabash & Ohio R.R. | added 1/95 | | NRHS |
| 14 | GSOR | Indiana Hi-Rail Corp. | added 7/95; eliminated 7/98; 7/2000 | | NRHS |
| 15 | GSOR | INDIANA HI-RAIL CORP.[(WOHO) WABASH & OHIO RAILROAD] | | | PWRC |
| 16 | GSOR | Indiana Hi-Rail Corporation | | | RSRV |
| 17 | GSOT | GREAT SOUTHERN TRUCKING CO | | | SCAC4 |
| 18 | GSOU | GLOBE OPUS SHIPPING LINE (UK) LTD | | GB | BIC |
| 19 | GSOX | Gold Standard Oils Ltd. | 1/1946-1/1950 | | NAKINA |
| 20 | GSOX | Valvoline Oil Co. | 7/1937-1/1941 | | NAKINA |
| 21 | GSOX | Galena Signal Oil Co. (Valvoline Oil Co.) | 7/1932-7/1935 | | NAKINA |
| 22 | GSOX | Valvoline Oil Co. | Apr-38 | | NRHS |
| 23 | GSOX | GOLD STANDARD OILS LTD. [VALVOLINE OIL CO.; GALENA SIGNAL OIL CO.] | | | PWRC |
