Tax-exempt dividends represent interest earned by ETFs or mutual funds holding tax-exempt bonds. Thus, the dividends are reported as tax-exempt interest on the federal income tax return (line 2a of Form 1040 or 1040-SR). They are fully tax free for federal income tax purposes, although they are taken into account in figuring the taxable portion of Social Security benefits. However, tax-free interest dividends may receive different treatment on the state tax level (they may be only partially or non-exempt).
The difference between amount realized and adjusted basis on the sale or exchange of capital assets. Long-term capital gains are taxed favorably. Capital losses are deducted first against capital gains, and then again up to $3,000 of other income.