Most pull tabs will give a variety of different Vdi's in different directions but them tabs that people pull off the can that aren't supposed to come off are the hard ones to distinguish because they usually read the same in different directions, they usually Vdi 25 most of the time but not always. I dig pull tabs all of the time because if there is gold down there I don't want to miss it. Nickels usually are 19 but there too are also variables, the war nickels will read higher sometimes because of the silver content in them. Lately I have been digging a lot of the lower VDI's and I've been finding nickels where you wouldn't normally think they'd be and I think it's because they are never going to lay perfectly flat under your coil in soil that has shifted from maybe a mole or who knows what. The best discriminator is still your eyeball but the V3i still shows which frequencies are hitting hardest even in the pinpoint mode. I seldom use the analyze mode with the trigger forward anymore because in my opinion analyzing in the run mode and pinpoint mode are enough for my satisfaction.