The Oxford English Dictionary has added LOL, OMG, and FYI to its list of published initialisms. I kid you not. But listen to this. It gets crazy. The OED post about these new additions to our increasingly digitized lexicon reveals that “As such usage indicates, many people would consider these recent coinages, from the last 10 or 20 years, and associate them with a younger generation conversant with all forms of digital communications. As is often the case, OED’s research has revealed some unexpected historical perspectives: our first quotation for OMG is from a personal letter from 1917; the letters LOL had a previous life, starting in 1960, denoting an elderly woman (or ‘little old lady’; see LOL n./1); and the entry for FYI [FYI phr., adj., and n.], for example, shows it originated in the language of memoranda in 1941.”
Read it all on the OED website.