| 601 | RSVC | RELIABLE SERVICE CO | | | SCAC3 |
| 602 | RSVC | ROSE VALLEY COLONY LTD | | | SCAC4 |
| 603 | RSVE | REACTION SERVICES INC | | | SCAC3 |
| 604 | RSVG | Rhein-Sieg Verkehrsgesellschaft mbH | Troisdorf | D | privat-bahn.de |
| 605 | RSVG | R & S CONTAINER SERVICE LLC | | | SCAC4 |
| 606 | RSVG | Rhein-Sieg Verkehrsgesellschaft mbH Troisdorf | City: Siegburg | D | TRAFFIC |
| 607 | RSVK | REED, STEVE TRUCKING LLC | | | SCAC4 |
| 608 | RSVL | R SCOTTSVILLE LUCKY TOURS | | | SCAC3 |
| 609 | RSVN | RESERVE INTERNATIONAL SERVICES INC | | | SCAC3 |
| 610 | RSVP | R S V P TRANSPORTATION INC | | | SCAC3 |
| 611 | RSVP | RSVP INTERNATIONAL LLC | | | SCAC4 |
| 612 | RSVQ | RESERVE TERMINALS COMPANY | | | SCAC3 |
| 613 | RSVS | RAIL SERVICES INC | | | SCAC3 |
| 614 | RSVU | JSC REFSERVICE | | RUS | BIC |
| 615 | RSVX | Railserv Funding Corp. | eliminated 7/1984; eliminated 7/1986 | | NAKINA |
| 616 | RSVX | Railserv Management Corp. | added 4/1980; eliminated 7/1984 | | NAKINA |
| 617 | RSVX | Railserv Management Corp. | added 4/80; eliminated 7/84 | | NRHS |
| 618 | RSVX | Railserv Funding Corp. | eliminated 7/84; eliminated 7/86 | | NRHS |
| 619 | RSVX | RAILSERV FUNDING CORP. (RAILSERV MANAGEMENT CORP.) | | | PWRC |
| 620 | RSVX | Railserv Management Corp | | | RSRV |
| 621 | RSVY | RODRIGUEZ SARABIA, VIANEY | | | SCAC4 |
| 622 | RSW | Air Switzerland | Callsign: Air Switerland, Planned startup 4Q02 with ex SQA A340-300 lsd frm Boeing | CH | AVCODES |
| 623 | RSW | Royal Skyways Co., Ltd. | Callsign: Royal Sky, | T | AVCODES |
| 624 | RSWI | RAWLS, S W INC | | | SCAC4 |
| 625 | RSWS | RIDEOUT SUNOCO & WRECKER SERVICE | | | SCAC3 |
| 626 | RSWZ | TRANSAMERICA LEASING INC [(REAZ) ST. LOUIS SOUTHWESTERN] | | | PWRC |
| 627 | RSWZ | TAL International | | | RSRV |
| 628 | RSWZ | TRANSAMERICA LEASING INC | | | SCAC4 |
| 629 | RSX | Red Sea Airlines | Callsign: Red Sea, | ET | AVCODES |
| 630 | RSX | A.M. Richter Sons Co. | 7/1930-10/1957; eliminated 10/1959 | | NAKINA |
| 631 | RSX | A.M. Richter Sons Co. | 4/38-10/57; eliminated 10/59 | | NRHS |
| 632 | RSX | A. M. RICHTER SONS CO. | | | PWRC |
| 633 | RSXC | ROSIE EXPRESS CO | | | SCAC4 |
| 634 | RSXD | RS EXPEDITE INC | | | SCAC4 |
| 635 | RSXE | ROADSTAR EXPRESS INC | | | SCAC4 |
| 636 | RSXM | RUSBELS TRANSPORT | | | SCAC4 |
| 637 | RSXN | RISEN TRANSPORTATION INC | | | SCAC4 |
| 638 | RSXO | R S D TRANSPORTATION INC | | | SCAC4 |
| 639 | RSXP | RED STAR EXPRESS LINES OF QUEBEC (1 | | | SCAC3 |
| 640 | RSXQ | R & S EXPORT TRUCKING CORP | | | SCAC3 |
| 641 | RSXS | R & S EXPRESS | | | SCAC3 |
| 642 | RSXS | R & S EXPRESS | | | SCAC4 |
| 643 | RSXT | R S TRANSPORT | | | SCAC4 |
| 644 | RSXW | R & S XPRESS | | | SCAC4 |
| 645 | RSXX | RAIL STUFF LLC | | | SCAC4 |
| 646 | RSY | The Airline iFly | IATA: H5, Callsign: Russian Sky, Designator H5 recalled by IATA | RUS | AVCODES |
| 647 | RSY | The Airline iFly | IATA: I4, Callsign: Russian Sky, IATA designator changed to F7. Designator H5 recalled by IATA | RUS | AVCODES |
| 648 | RSY | The Airline iFly | IATA: F7, Callsign: Russian Sky, IATA designator changed from I4*. Designator H5 recalled by IATA | RUS | AVCODES |
| 649 | RSYI | RTS DELIVERY INC | | | SCAC4 |
| 650 | RSYM | ROTH, SYLVESTER M | | | SCAC3 |
| 651 | RSYN | ROGERS SPRAYERS INC | | | SCAC4 |
| 652 | RSYS | ROYCE SYSTEMS/SERVICES INC | | | SCAC3 |
| 653 | RSYT | R S T INC | | | SCAC3 |
| 654 | RSYX | Refined Sugars, Inc. | added 7/1981; eliminated 10/1986; 1/1994-7/2005 (not listed) | | NAKINA |
| 655 | RSYX | Refined Syrups & Sugars, Inc. | added 7/1980; eliminated 7/1981 | | NAKINA |
| 656 | RSYX | Refined Syrups & Sugars, Inc. | added 7/80; eliminated 7/81 | | NRHS |
| 657 | RSYX | Refined Sugars, Inc. | added 7/81; eliminated 10/86; 1/94-7/2000 | | NRHS |
| 658 | RSYX | REFINED SUGARS INC. | | | PWRC |
| 659 | RSYX | Refined Sugars | | | RSRV |
| 660 | RSYX | REFINED SUGARS INC. | | | SCAC4 |
| 661 | RSZ | Air Service State Company | Callsign: Hunser, | H | AVCODES |
| 662 | RSZT | REED SPECIALIZED TRANSPORT INC | | | SCAC4 |
