rude slang An initialism of "read the fucking instructions," an exclamation of frustration and exasperation directed at someone who has asked a question or series of questions that have already been answered in the instructions for something. Would you stop asking such boneheaded questions and just RTFI? I don't have time to hold your hand on every project we do. I don't understand how you could be having so many problems installing the software. RTFI, dude.