Looks like thr 5.7 just became a NATO caliber
New NATO Caliber – FN Herstal's 5.7x28mm
Thirty-five years after it was invented, the 5.7x28mm caliber is now standardized by NATO. The new standardization comes after the 5.56x45mm and 7.62x51mm calibers, which were both designed by FN Herstal, and standardized by NATO in 1957 and 1981 respectively.
www.thefirearmblog.com