virtually fat free means a product has 'some fat' like .2%
so does fat free on food labels..
fat free means you should check if it is laden with sugar instead ie fat free flavoured yogurt usually has 4 teaspoons of sugar anyway in the often synthetic fruit bit.
I've seen fat free pototo products... These are a con because a potato is not fatty to start of with, it's a con.
A trace means it's so bl##dy low it aint easy to find like maybe .2 milligrams or near to zilch, nadda, niche, none!!
Nuts and fruits with a trace of fat or usually good fat but so low who cares.