Just that the US meaning of the term differs from what you are probably used to. Not to derail the thread any further, but in FAA parlance, MSA is not a procedural altitude. It is merely an altitude which should keep you out of the weeds if you are off the procedural track and within 25 nm of the NAVAID depicted.
From FAR 97.3 Quote:
MSA means minimum safe altitude, expressed in feet above mean sea level, depicted on an approach chart that provides at least 1,000 feet of obstacle clearance for emergency use within a certain distance from the specified navigation facility or fix.
Interesting. I noted the reference to AIM in the previous post too, different ways to skin a cat.
For where I come from (both training and operations) MSA is calculated in the same manner, providing 1000 ft obstacle clearance. Given the fact, that intermediate approach segment MOC is 500 ft - just for comparison, I am happy to use MSA as an operational altitude when the situation of the day requires to do so.
This would be illegal in the US, ok. Learn something every day: ticked.