The contemporary square-drive screw has all but replaced the Robertson screw proper and is commonly referred to as a Robertson because it has practically identical drive dimensions and the same colour identification system, but the contemporary square drive socket has parallel sides rather than tapered.
We all learned what a phillips is, so we can learn what a robertson is.
But, yeah, most of us need a reminder for now.
Except apparently Robertson isn’t used anymore.
https://en.wikipedia.org/wiki/Robertson_screw
So it is a square drive, not Robertson.