I just dropped by a local retail nursery and was horrified by the hardiness signs they had hanging on their citrus, these were big letter size laser printed signs with the name, price, and hardiness scale at the bottom. Unfortunately the manager was not in, and I did not think it would do any good to tell the teenager behind the sales counter.
A few examples:
Owari Satsuma zone 10 only
Brown Select Satsuma zone 9 & 10
Blood Oranges zone 6 -10
Hamlin Oranges 7-10
Meyers Lemon 6-10
At first I thought they were simply backwards, but there were a few oddballs thrown in
Note this nursery is along the 9a / 8b line (within a mile or two)