Of course and I would be very interested to see a reliable source that says ISO and gravitational are equivalent as the article currently does save for centrifugal any gravitational effect is due to reference frame acceleration Very true To make sense the statement would need a qualifier similar to the statement currently in the article and it would have the same problem stating two things are the same if you ignore their differences That is why I don t see how the current statement in the article is any better than 2 0 equals 5 0 save for 3 0 Although it is correct it gives the wrong impression that 2 equals 5 or that ISO is equivalent to the gravitational definition