your mileage may vary

from Jargon File (4.4.4, 14 Aug 2003)

Your mileage may vary
 cav.

   [from the standard disclaimer attached to EPA mileage ratings by
   American car manufacturers]

   1. A ritual warning often found in Unix freeware distributions.
   Translates roughly as "Hey, I tried to write this portably, but who
   knows what'll happen on your system?"

   2. More generally, a qualifier attached to advice. "I find that
   sending flowers works well, but your mileage may vary."

from The Free On-line Dictionary of Computing (8 July 2008)

Your mileage may vary
YMMV

   (Standard disclaimer attached to EPA mileage ratings by
   American car manufacturers) A ritual warning often found in
   Unix {freeware} distributions and elsewhere.  Translates
   roughly as "Hey, I tried to write this portably, but who
   *knows* what'll happen on your system?"

   [{Jargon File}]

   (1994-11-10)

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