Today I left my meter at home by accident. Thought about going back home to get it, and/or curtailing my usual activities, decided not to.
I was talking about this to another diabetic and she says she doesn't let other people use her meter because it messes up her averages and confuses the doctors.
I let everybody and anybody use my meter. Mine is an Accu-Chek aviva, and I can press a little button to star any results that aren't mine, although they still come up in the averages. However, since I check frequently and a normal blood sugar is not an outlier for me, I don't think that having somebody else's number on there every other week matters.
Her meter doesn't have a button for marking special numbers.
My 7 day average at the moment is 108, representing 34 of my numbers above 65 and 5 of my numbers below 65, and a nondiabetic classmate's 100.