(1) Dividends are a separate category of income than capital gains.
(2) Mutual fund capital gains reported on Box 2a of Form 1099-DIV are capital gains incurred by the mutual fund itself on its own transactions. These are passed on to shareholders. From a tax perspective, this is one of the disadvantages of a mutual fund. You then have individual capital gains/losses when you sell your shares.
Why? Because that is the way tax law is writtten.
