[lbourdages]

Well, nautical miles are the standard unit in the context of aviation, so I don't think it's all that bad. "mi" refers to a different unit.

[gibibit]

True, "nm" initially seemed to be nautical miles, but then this square meters thing appeared. The point is that "m" should be meters, but "mi" would be a more customary abbreviation for miles in the U.S.

[lupusreal]

They shouldn't have switched from nautical miles to miles. The area should have been expressed in square nautical miles.