IATEFL
International Association of Teachers of English as a Foreign Language
British-based international association.
IBO
International Baccaleureate organisation
The International Baccalaureate Organization (IBO) is a recognized leader in the field of international education, encouraging students to be active learners, well-rounded individuals and engaged world citizens.
IELTS
The International English Language Testing System
This is an internationally owned and globally recognised direct English Language assessment system. It is primarily used by those seeking international education, professional recognition, bench-marking to international standards and global mobility.
IMO
In my opinion