U.S. definition of "statute mile"
Would you say that the definition of the U.S. statute mile (NOT necessarily the survey mile) is exactly 1609.344 km (same as international mile) or exactly(5280 * 1200)/3937 m (same as survey mile). A Federal Register notice seems to say the statute and survey miles are identical, but other sources disagree.
Since no one uses miles for high-precision measurements, it makes no practical difference. However, if various definitions are embedded in software conversion functions, discrepancies can creep in that are greater than the truncation error of the computer, and it could be a pain to track down where the problem came from.