Okay. Did as you asked. Clarification as requested:
"Descend to FL140, level 40d OCK" Easy bit. Sets a scene and all that. Good instructional technique
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"maintain M.80", still easy, no? M0.80 (or whatever this Bo' or Airbus is dragging along at) initially in the descent....
"then 280kts." Getting more complex, but M0.80 at (say) FL370 is about 260kts indicated. A constant Mach descent will result in an increasing IAS. This part therefore means trap 280kts when you see it (FL340-ish) and don't just maintain M0.80 allowing the IAS to go up to 350kts prior to reducing back to 280kts later on 'cos you'll bump into someone. The
"then" bit is to emphase that you're not to go for 280kts immediately because in this case that would involve a 20 kts acceleration to about M0.85 (and a compromised separation) at FL370 rather than a M0.80/280kts descent profile (the desired result).
"Do not exceed 280kts indicated" Back to easy, really. Take the occasional look at the ASI, and irrespective of Mach don't let the big hand point to more than 280 at any stage. Sounds obvious, but it seems it wasn't to this bloke.
Well, it was only my go at putting it into a short instruction that even the special needs pilot quoted by zonoma would be able to comply with. Look forward to your improved suggestion.......
PS: All meant a little tongue-in-cheek, just in case anyone felt like a pprune-type rant..........