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.