| CHAIN | Canadian High Arctic Ionospheric Network 
| Others |
| CHAIN | China HIV AIDS Information Network
| Others |
| CHAIN | Collaborative Healthcare Associated Infection Network
| Others |
| CHAIN | Collective Humane Action And Information Network
| Others |
| CHAIN | Communication Help Advise Information And News
| Others |
| CHAIN | Communities Helping Adults In Need
| Others |
| CHAIN | Contact Help Advice Information Network
| Others |
| CHAIN | Contact, Help, Advice, and Information Network
| Others |
| CHAIN | Contrast Hierarchical Alignment and Interaction Network
| Others |
| CHAIN | Controlled and Harmonised Aeronautical Information Network
| Others |