The title on this FAQ item conveys slightly the wrong impression:
* Why doesn't my Rio Car work in my Mark 2 docking sled?
because, as mentioned elsewhere in the FAQ, the Rio Car and Mark 2
docking sleds are interchangable. I understand the logic behind
phrasing it like this---the user is expected to have got a Mark 2
working and is now wondering why their new Rio Car doesn't---but
even so, the problem is not in the sled.

Rather than try to make the title more accurate but much longer,
how about inserting a sentence in the answer along the lines of:
The problem is not in the sled, which is compatible (identical?)
between the two models, but in how the Mark 2 and Rio Car differ
in handling faults in the fuses or power supply.
_________________________ Robin O'Leary