Commonly used abbreviations in English are:

OIC--Oh I see (I understand);

BRB--Be right back (come back immediately) ;

BFN--Bye for now (goodbye);

LOL--Laughing out loud (laughing);

ASAP --As soon as possible (As soon as possible);

BTW--By the way (by the way);

JK--Just kidding (just kidding);

TTYL - -Talk to you later.

Abbreviations representing various organizations or institutions:

1.APEC (Asia-Pacific Economic Cooperation) Asia-Pacific Economic and Trade Cooperation

2.IOC ( International Olympic Committee) International Olympic Committee

3.ISO (International Organization for Standardization) International Organization for Standardization

4.WTO (World Trade Organization) World Trade Organization

2. Abbreviations representing various systems:

1.GPS (Global Position System) Global Positioning System

2.GSM (Global System for Mobile Communications) Global Mobile Communications System

3.CIMS (Computer Integrated Manufacturing System) Computer Integrated Manufacturing System

4.ITS (Intelligent Transportation System) Intelligent Transportation System

5.NMD ( National Missile Defense) National Missile Defense System