CYA should be used when you are either ending off a message, a chat or getting out of an online environment in a friendly, informal way. It is perfect to message a friend, say a goodbye after having discussed a topic in a classroom, or a casual conversation. CYA is most effective where you need not have an official farewell and just require something casual and informal. It is use particularly during the regular communication when concise expressions are used to make the communication process quicker and easier.