I think this is pretty interesting.

This website:

http://visa.via.infonow.net/locator/...r/NewSearch.do

Shows what spending categories of Visa considers each merchant to be in. This can be a useful website for figuring out which companies are counted as "office-supply stores" for the Ink cards, for example.

And, furthermore, if you think you're going to be purchasing gift cards at Staples and telling Chase that these were regular office supplies, you may be interested in learning what level of data that merchant provides to the card company.

http://visa.via.infonow.net/locator/...DLDisplay.html