What does “best practice” really mean?

Don DeLauder of Medrad said at a recent Medical Device Conference, “Best Practice means something I may or may not have done that may or may not have worked.”  He’s got a point.  I’ve heard people assert “best practice” many times when they mean “Please buy this” or “I hope to be able to do this” or “It sounds better this way.”  In portfolio management, I have heard “best practice” used countless times to really mean “common practice” — what other people are doing, not what works.  Not that best practices are bad, who could argue with them, but too often the standard for recommending them is too low.