Messengers have transformed and revolutionized the way we communicate. Messaging has caused steep spike in use of Shortened Language (SLANG). It is really helpful at times and really convoluted if you are not well versed with SLANG. Some may use Ok as K, OK or even OKAY. Does it even matter? As long as it is understandable and conveys the meaning, it doesn’t matter. Personally, I am of the opinion that SLANG should be used in limit. As they say, Anything in Excess is Bad. Just imagine someone texting you something like IYKWIM (If you know what I mean…). At first you will be like what is this person trying to say (if you are not well versed with SLANG). This is exactly where I think, it does matter. In such scenarios, use full forms.
You may not use SLANG but it is also important that you get versed with some amount of SLANG. Human Brain is one of the most amazing thing. It so happens that, when you look at something regularly, the brain picks it up immediately and interprets it. In short, imbibing new SLANG terms may not take much time.
Bottom Line: Avoid using SLANG but do get versed with it because not everyone is going to stop using SLANG.