The same people can make both designations. NATO is a metric specification not a manufacturer.
NATO designations signified by a circle-plus head stamp are indications of a round that meets requirements AND HAS BEEN TESTED by NATO certified locations - there are one or two in the US IIRC.
I might note that the major requirement for this round is muzzle velocity and comporting to the dimensions required.
If it doesn’t have the cirle-plus, then it isn’t a ‘true’ NATO round.
Geez. Did he really have to give the /s? He was joshin’ ya!