Tootler, what you said regarding "use by" vs. "best by" jibes pretty much with my understanding. The only place where I might disagree - a matter of judgment - is on whether a "stale" cookie or package of macaroni necessarily needs to be thrown out. I think that depends partly on what your budget is like, for instance. Sometimes the main disadvantage to eating "stale" food is that it doesn't taste fresh, but with some foods "stale" may mean "rancid oils."
The important thing I want to communicate to the other caregivers is that not all product dates on packages are "best by" or "use by" dates, and they often do not mean the product needs to be discarded soon after that date.