| Acronym | Definition |
|---|
| RER | Regione Emilia-Romagna |
| RER | Rental Equipment Register |
| RER | Réseau Express Régional (French commuter rail in Paris) |
| RER | Rough Endoplasmic Reticulum |
| RER | Respiratory Exchange Ratio |
| RER | Radio Edge Router |
| RER | Re-Recording |
| RER | Read Error |
| RER | Renewable Energy Resource |
| RER | Real Exchange Rate |
| RER | Review of Educational Research |
| RER | Replication Error |
| RER | Radiological Emergency Response (various locations) |
| RER | Regional Express Network |
| RER | Recurrent Exertional Rhabdomyolysis |
| RER | Reed Electronics Research (Reed Business Information) |
| RER | Real Estate Resources, Inc. (Cincinnati, OH) |
| RER | Reading to End Racism (various locations) |
| RER | Relative Energy Ratio |
| RER | Régimen Especial de Renta (Spanish: Special Income Scheme; taxes) |
| RER | Radio Est Réunion (French radio station) |
| RER | Respiratory Exchange Rate |
| RER | Remediation Effectiveness Report |
| RER | Research Expenditure Report |
| RER | Rubberized Equipment Repair |
| RER | Resting Energing Requirement |
| RER | Resource Efficiency Ratio |
| RER | Receiver-Exciter Ranging |
| RER | Repair Effectiveness Rating |
| RER | Remote Read-Out |
| RER | Radio Expenditure Report |
| RER | Reactor Event Report |
| RER | Radiation Effect Reactor |
| RER | Reusable - Expendable - Reusable |
| RER | Redeye Reduction (camera technology) |
| RER | Regional Expected Results (World Health Organization) |
| RER | Record of Environmental Review (US FEMA) |
| RER | Recognition Error Rate (speech synthesis design value) |
| RER | Resting Energy Rate |
| RER | Radar Echo Return |
| RER | Resource Evaluation Report |