BFF is an initialism that stands for "Best Friends Forever". It is used to refer to a close friend or best friend. The term has been in use since at least 1996. BFF is mostly used by younger people in informal communication, such as texting and social media. It can be written in uppercase or lowercase letters, and there are no hard and fast rules for writing it. If used in formal communication, it is recommended to pick one of the two capitalization options and use it consistently. The label "BFF" does not suggest restriction, and according to ones personal belief or understanding of the phrase, one person may or may not have more than one BFF at any given time.