ReelBreak:
I don't have an NEC reference handy....but, I had similar situation; got labels stating 'more than ONE disconnect feeds this panel (equipment, machine, etc). Probably in WW Grainger catalog, or at supply house.
Identifying the source of power is required, and lockable in off if not 'within sight', etc.
If I get a chance tommorow, I'll get an NEC ref.
John
