There is a massive culture of this on the internet already. This is in no way a new phenomenon (doo doo doo-doo-doo). But I think that, especially when trying to convey friendliness or lighthearted intentions, lowercase is the way to go. This is not to say that this is the only way to be lighthearted in conversation using text. When in doubt, using tone tags like /lighthearted or /lh for short is incredibly helpful, especially for those with bad sarcasm indicators and for overthinkers (link to some tone tags here! Enjoy!) But punctuation and grammar (or lack thereof) can be incredibly powerful.

  for example, typing like this is usually my default. here it’s difficult, especially because i’m typing in a word document and have to correct the autocorrect the words to make a point. but then, using this practice, one can properly emphasise something (like done on tumblr) by capitalising The Thing™. there have been numerous tumblr posts analysing and extracting this, so i won’t go into too much detail here, but you see my point?

  I think most people on the internet have gathered that a single “k” in response to anything can come across as quite aggressive. An “ok” on its own is also quite confronting, depicting anything from a depressive state to “I’m absolutely fuming right now, but don’t want to seem like a bitch by just saying ‘k’”. “okay” is slightly less aggressive, but can seem apathetic. All of these change when made capital. “K” and “OK” are both a simple “message received,” while “OKAY” is playful when all parties are using capital letters, but can be quite confusing and concerning when it isn’t called for. It may be that the person saying it has simply tried to reply to an automated text, but clicked on the wrong name. “Ok,” with the k lowercase, generally isn’t used much with people in my age group. I don’t know what to say about that one. I’ll do more research and report back.

  My mother discovered “Okies” as a very passive and lighthearted affirmation. I’m an “okay cool” kinda gal. One of my brothers started using “OKIES” and has continued terrifying the whole family.