<jargon> (YMMV) The disclaimer American car manufacturers attached to EPA mileage ratings. A humourous way of saying that the thing under discussion will not necessarily give you the same results as the author. Often used to convey the hardware dependence of Unix freeware distributions.
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Nearby terms: Yourdon/Demarco « Yourdon, Inc. « Yourdon methodology « Your mileage may vary » youtube.com » YouTube, Inc. » Yow!