FYI, LOL, OMG, J/K and TMI are among the most common acronyms in text messaging. FYI is short for "for your information." LOL indicates that the person typing is "laughing out loud." OMG is a popular substitute for "Oh my God!" TMI and J/K offer commentary on something that a person or her texting partner has just typed; they stand for "too much information" and "just kidding," respectively.
BTW and IMHO are popular acronyms that can offer commentary before or after recent statements. They stand for "by the way" and "in my humble opinion." STBY is a popular acronym of pity to a texting partner, and SITD can signify pity for its writer or anyone else; the two stand for "sucks to be you" and "still in the dark," respectively.
For affection and praise, WYWH, ILY, LYLAS and MHOTY stand for, respectively, "wish you were here," "I love you," "love you like a sister" and "my hat's off to you." Similarly, TYVM is a term of appreciation meaning "thank you very much."
DBEYR and RBTL are popular text acronyms to caution the reader about something she has either recently read or experienced. They stand for "don't believe everything you read" and "read between the lines." BRB and TTYL can briefly suspend or end a text message conversation. They stand for "be right back" and "talk to you later."