A FW member described the problem
he had when he used his Visa Citi credit card to pay for an online education course. Citi charged him as if it were a cash advance with $20 in fees.
Based on what others have reported in that thread, it appears Citi now classifies anything remotely related to finance as a cash advance. This might have been due the widespread use of Citi credit cards being used to fund bank accounts and earn rewards.