Mike was close. It's a fee that is no longer legal, hence it's $0..on your contract. Broker commissions on both sides (seller/buyer) often read as follows now "7% + $495 broker commission" *7% is just an example, as mandated, there is no set rate of commission.
It's a fee charged by the brokerage on each transaction. Usually, it's charged to both buyers and sellers. Many brokers need this type of income to do business in the manner they do. For them, it's an income source. I've seen such fees as high as $495 and as low as zero. One way or another, the brokerage needs to make a profit....this is one way....there are others. Most likely, your broker has another way and it's $0. Rejoice!