| Abbreviation | Definition |
|---|---|
| REGEDIT | Registry Editor |
| REM | Randomly Evolving Machinecode |
| REN | Re-Name |
| REP | Repeat |
| REPE | Repeat While Equal |
| REPNE | Repeat While Not Equal |
| REPNZ | Repeat While Not Zero |
| REPZ | Repeat While Zero |
| REQ | Returnn if Equal |
| RET | Return from Procedure |
| RETF | Return Far |
| RETN | Return Near |
| RF | Read Filter |
| RFB | Read From Buffer |
| RFR | Residence Flag Reciprocal |
| RFU | Residence Flag Unilateral |
| RGA | Reports to the General Assembly |
| RGAR | Rate Gyro Assembly Right |
| RHA | Residence Hall Assembly |
| RHP | Re-Heat Pizza |