The Predominate USA HF Digital Frequencies Are:
10 Meter Band: 28.110 - 28.125 Mhz 20 Meter Band: 14.065 - 14.090 Mhz
12 Meter Band: 24.920 - 24.930 Mhz 30 Meter Band: 10.130 - 10.145 Mhz
15 Meter Band: 21.060 - 21.090 Mhz 40 Meter Band: 7.060 - 7.080 Mhz
17 Meter Band: 18.100 - 18.110 Mhz 80 Meter Band: 3.620 - 3.640 & 3.575 - 3.585 Mhz
6 Meter Band: 50.290 - 50.292 Mhz

Legal Wide Band HF Digital Frequencies (MT-63 and Pactor III modes):

28.120-28.189 MHz,    24.925-24.930 MHz,    21.090-21.100 MHz

18.105- 18.110 MHz,    14.0950-14.0995 MHz,    14.1005-14.112 MHz

10.140-10.150 MHz,    7.100-7.105 MHz,     3.620-3.635 MHz.

Confusion over band space is the obvious down-side as new and old modes compete for band space. Crowding on a single band like 20 meters is partly to blame for this issue. Fortunately the new modes, like MFSK16, are designed to improve performance inside a wide range of operating conditions. This should allow for increased ham band usage to relieve crowding and extend contact opportunities as propagation changes to favor different bands. The current condition of the eleven year "sun spot cycle" has increased the usable spectrum for propagation on the HF bands. I don't know what is going on with the phone portion of the ham bands, but these are exciting times for us digital operators!