I have struggled with the correct nomenclature, inch, imperial, SAE etc. None of them are wrong, none are correct. The closest I have come is U.S. Customary, but no one recognizes it.
I bought a set of import tie-down clamps and studs for the mill. I specifically ordered a set that advertised 1/2-13 UNC. I was half-way through cutting the nuts down from 22mm to 3/4 in. when I realized the damn things were M12x2 threads. The seller got to keep his sh*tty feedback and I got to keep the *!##!!* clamp set.