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.”