Used on any site that has a word limit in which you do not have enough words to use proper grammar or to have enough words to complete thoughts in proper language(*English). Abbreviations are commonly used.
Person: Ur so stpd, y da HLL wod u say dat ind of grbage? oowig
Idiot who doesn't know oowig: Learn how to spell retard, and use proper grammar, stupid.(This person defines the word idiot)