FYI - For Your Information
For Your Information, in form of its abbreviation FYI, is an Internet Slang, used in email, Instant Message and Chatting. It represents a situation in which we want to give any informational message to the other person.
Like In a Conversation :
Person 1 : Hi Steve
Person 2 : Hello Sir! How can i help you
Person 1 : Can i get a printout of my documents
Person 2 : FYI, we're out of paper
It may be considered informal, if not used properly. The tone and situation defines the sentence that whether it is arrogant or not. If possible, we should try to avoid it in our conversation.