| Information Strategy Systems And Economics | Academic & Science |
| Information Systems Security Engineering | Academic & Science |
| Institute for the Study of Society and Environment | Academic & Science |
| Information System Security Engineer | Business |
| Institute for the Study of Somatic Education | Community |
| International School to School Experience | Community |
| Intel SIMD Streaming Extension | Computing |
| Intel Streaming Simd Extensions | Computing |
| Internet Sse | Computing |
| Integer Sse | Computing |
| Institute for Software and Systems Engineering | Computing |
| Information Security Solutions Europe | Computing |
| Innovations in Systems and Software Engineering | Computing |
| In-situ Spectroscopic Ellipsometry | Electronics |
| Imagery Support Server Environment | General |
| Information Support Server Environment | General |
| Interactive Source Separation Editor | General |
| International Salon Spa Expo | General |
| Integer Streaming SIMD Extensions | General |
| In Situ Support Equipment | General |
| Independent Safety and Security Examiner | General |
| Institute for a Secure and Sustainable Environment | Governmental |
| International Secondary School Eindhoven | International |
| International Students for Social Equality | International |
| International Society for Sample Environment | International |
| Internet Streaming SIMD Extension | Internet |
| Internet Streaming SIMD Extensions | Internet |
| Irish Survey of Student Engagement | Regional |
| International Soccer School of Excellence | Sports |
