FYI stands for "for your information." It is an abbreviation used to share information with someone, typically indicating that no action or response is required from the recipient. FYI is commonly used in both informal and formal communication, such as emails, text messages, and conversations, to call attention to information that the sender thinks the receiver should know

. The term originated in the 1930s among journalists as a way to mark messages intended only for the recipient's eyes, not for publication, and it gained popularity with the rise of email and online communication

. In professional settings, FYI is often written in all caps ("FYI") especially in email subject lines to look more formal, while in casual contexts it can be lowercase ("fyi")

. Examples of usage include:

• "FYI, the meeting has been rescheduled to 3 PM."
• "Just FYI, the appointment was cancelled and can't be rescheduled for two weeks."
• "FYI, the final project is due on Thursday."

Overall, FYI is a concise way to pass along information without expecting a reply or action