| Rank | Abbreviation | Meaning |
|---|
| ***** | ECSI | European Customer Satisfaction Index
| |
| *** | ECSI | European Consumer Satisfaction Index
| |
| *** | ECSI | Export Cargo Shipping Instruction
| |
| ** | ECSI | Electronic Control Security, Inc.
| |
| ** | ECSI | Études, Conseils et Solutions Informatiques
| |
| ** | ECSI | Educational Computer Services Inc
| |
| * | ECSI | Environmental Consulting Services Inc
| |
| * | ECSI | Educational Computer Systems Incorporated
| |
| * | ECSI | Engineering and Consulting Services Inc
| |
| * | ECSI | Energy Control Systems Inc
| |
| * | ECSI | Editorial Committee of the Swedish Institutes
| |
| * | ECSI | Enfermedades Crónicas Socialmente Invisibles
| |
| * | ECSI | E Commerce Systems Inc
| |
| * | ECSI | Environmental Control Systems Inc
| |
| * | ECSI | Electronic Commerce Solutions International
| |
| * | ECSI | Electronic Communication Systems Inc
| |
| * | ECSI | Early Childhood Systems Initiative
| |
| * | ECSI | Environmental Crime Scene Investigation
| |
| * | ECSI | EarthKeeper Center for Self Improvement
| |
| * | ECSI | East China Shipbuilding Institute
| |
| * | ECSI | Environmental Cleanup Site Information
| |
| * | ECSI | Electronic Commerce Solutions Incorporated
| |
| * | ECSI | Electronic Chips & Systems Design Initiative
| |
| * | ECSI | Edgewater Computer Systems Inc
| |
| * | ECSI | Energy Conservation Systems Inc
| |