YMMV ["Your Mileage May Vary"] is a slang acronym used in social media, texts, emails, and generally anywhere else online to express the caveat that one understands that someone else may have a different opinion on the subject under discussion, based on their own experience.
Comes from old TV ads that touted high gas mileage for various brands of cars. "34 MPG highway, 25 MPG city. Your Mileage May Vary."
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