So I was looking at my credit card propaganda and read that VISA determines which gas purchases
qualify for the 5% reward. I wondered if diesel was included. So I called my credit union.

They said VISA uses a Merchant's Category Classification (MCC) Code to make the determination. When
I filled up at the Sunoco, the code was 5542 and awarded the 5% reward. However, when I filled up at
the Hess, the code was 5541 and did not get the 5% reward. The lady at the credit union could not
tell me why this was so.

So I called VISA. They were not cooperative at all - told me my credit union made all the rules and
I should ask them.

Finally got on the internet and found this: http://tinyurl.com/853sptx

That helped a little, at least I now knew the difference between 5542 and 5541. The first is
'Automated Fuel Dispensers' and the second is 'Service Stations'. While looking for info, I also
found this: http://www.irs.gov/irb/2004-31_IRB/ar17.html I suppose I should have known the IRS was
involved in this somehow.

Anyway, I called Pilot Travel Centers, where I buy fuel when on the road, especially in the evening
when we stop for the night ('cause they allow overnight parking by RV's for nothing!). I asked them
what their 'Merchant's Category Code' was, but the lady couldn't help me. She had no idea what I was
talking about, but she said she'd get back to me with an answer.

Well, surprisingly, she did. If I bought fuel and swiped my card at the pump, the transaction was
under MCC 5542. If I came inside and paid, the transaction was under MCC 5541. If I ate at the
restaurant there was a different code, and if I bought stuff from the store there was another code.
I don't remember them all.

Anyway, the moral of the story is this: If you get cash back, or rewards for purchasing fuel, make
sure you're careful about the MCC. I'll no longer buy fuel at a station (such as my local Hess)
where I have to pay for it at the counter. Hess may be a couple cents cheaper than Sunoco, but I
lose the $0.20/gallon I get back in cash from VISA.