Acronyms are an accepted part of using the Internet and texting, with thousands of abbreviations and emoticons available. However, in business and professional settings, abbreviations in text should be kept to a minimum or eliminated altogether. Certain phrases, such as "WTF," are always unprofessional and inappropriate in these contexts.
Among friends, using abbreviations and other shorthand tricks in text is so commonplace that people are concerned it impacts their ability to learn standard English. Studies demonstrated that in university students, instances of SMS language used in final exams appeared in almost negligible amounts, implying that people are aware of when textspeak is, and is not, appropriate.
For professional texting etiquette, to avoid appearing overly informal or rude, Business Insider suggests limiting usage to commonly known abbreviations with obvious definitions. However, it may be better to err on the side of caution and type out every word and sentence fully to avoid any issues with clarity.
Common abbreviations include "u," which stands for you; "LOL," or laughing out loud; "AFAIK," or as far as I know. There are enough different words, abbreviations and variations that Netlingo has compiled an international dictionary of jargon, which explains abbreviations that appear in other languages.