BT Group (LSE: BT.A) shares are on a forecast dividend yield of 7.4% for 2024. Forecasts show it steady in the next few years, and even rising a bit. And to top the cake off with icing, the dividend cash should be around twice covered by earnings. On the face of it, it sounds like BT shares could be a great long-term income buy. And I think they might indeed be. I can’t ignore the terrible 10-year share price record, though. Before I try to work out what I might earn in income from BT shares, I need to think about the dividend a bit. Some things I like well enough, others not so much. BT dividends score well on the yield, which is well up in the top half of the FTSE 100. I like to see dividends being covered by earnings, so that’s another plus for BT. My favourite dividends come from cash cow companies that don’t need to keep investing huge sums to keep going. BT has reasonable, and rising, cash flow. But, boy, does it need to invest big to grow its broadband and other offerings. Then I also prefer firms that are not under debt...