I've had plenty of credit card transactions that I look at on the statement and wonder 'what on earth did I buy there?'; the most memorable (that wasn't fraud) was paying for a phone for a friend - the name was so inexplicable (and not susceptible to my usual solution of searching online) that I blogged it here and still get about a comment a month from someone saying now they know what their transaction with the same company is about.
I just copied a month's worth of transactions from my trusty Virgin Amex (if you too want to get flying club miles for shopping, let me know as I have a friend code somewhere that gets us both 1,000 extra miles) and I didn't bother to click the Show details link, but the extra details copied anyway and they're useful. (so rare for a bill)
Given that the credit card company has approved the merchant, they pretty much know what they do; now you get a store category on the transaction - so that small amount I just couldn't remember turns out to be himself's Christmas card. I wonder if this is to compete with sites like Mint that help you categorise your spending? Or to help us spot fraud? Or just to make our lives easier (I do like Amex for how often they do things that make life easier, though I appreciate they charge merchants more so they can do so). Amused they class Wal-Mart as a discount store though ;-)