Timesaving online abbreviations like LOL, OMG and IMHO are now part of the official English language. The Oxford English Dictionary (OED) announced the addition of several initialisms to its only dictionary, adding some interesting trivia behind the origins of these Internet-associated expressions.
OED explained that although initialisms like OMG (Oh My God), LOL (Laughing Out Loud) and IMHO (In My Humble/Honest Opinion) are strongly associated with the language of electronic communications, their origins are surprisingly predating the Internet era.
For example, OED found a quotation for OMG in a personal letter from 1917, or FYI (For Your Information) originated in the language of memoranda in 1941. Also, apparently the LOL expression had a previous life, starting in 1960, denoting an elderly woman (Little Old Lady).
OED notes that some expressions like OMG and LOL are used outside electronic communication contexts as well, including print and spoken use, in the form of more than a simple abbreviation:
"The intention is usually to signal an informal, gossipy mode of expression, and perhaps parody the level of unreflective enthusiasm or overstatement that can sometimes appear in online discourse, while at the same time marking oneself as an ‘insider' au fait with the forms of expression associated with the latest technology."
If you're not familiar with the online slang, you can always check out this Internet slang dictionary and translator. Just enter the text slang you want to translate and you're done. TTYL