Software often puts the version in the name. Which is the same as the S7 designation in the case of said combine. S7 is just a restyled S7x0 series combine, which was the successor to the S6x0 series.

It's not a perfect system. Before the S6x0 was the 9x70STS series, after the 9x60STS series, and the 9x50STS series. You can find a version number in there, albeit not a perfectly sequential one. Although that's nothing new. Windows 3.1 turned 3.11, 95, 98. iOS 17 turned 26. You get the picture.