| REL | Radio Engineering Laboratories 
| Others |
| REL | Radio equipment list
| Others |
| REL | Radioactive Electron Laser
| Others |
| REL | Randford Earls Labs
| Others |
| REL | Rapid Engine League
| Others |
| REL | Rear End Loader
| Others |
| REL | Recommended Exposure Level
| Others |
| REL | Recommended Exposure Limit
| Others |
| REL | Redhat Enterprise Linux
| Others |
| REL | Redwood Expression Language
| Others |
| REL | Reference Exposure Level
| Others |
| REL | Regal Limited
| Others |
| REL | Regional Education Laboratories
| Others |
| REL | Regional Educational Laboratories
| Others |
| REL | Regional Educational Laboratory
| Others |
| REL | Related to Seller
| Others |
| REL | Relation
| Others |
| REL | Release
| Others |
| REL | Released
| Transport, Railways |
| REL | Reliant
| Others |
| REL | RELict
| Others |
| REL | Research Enterprise Limited
| Others |
| REL | Research Enterprise Limited Quebec
| Others |
| REL | Research, Evaluation and Learning
| Others |
| REL | Resource Equipment Ltd
| Others |
| REL | Reversible Express Lanes
| Others |
| REL | Richland Engineering Limited
| Others |
| REL | Rights Expression Language
| Others |
| REL | Robert Edward Lee
| Others |
| REL | Rosen Electronics Letter
| Others |
| REL | Rules Enforcement Level
| Others |
| REL | Trelew, CB, Argentina
| Others |