BTW is a casual short form and is mostly applied in casual texting and social media communication, and friendly emails. It is casual, and it is ideal when conversing with friends or peers. In formal communication, though, which could be business emails, academic or work-related chat, BTW should be avoided. In its place, it would be appropriate to use full-fledged phrases such as Addition or By the way to make it sound more correct. Learning about the appropriate time to use BTW can make you stick to the professionalism and clarity in various kinds of communication.