Ford Super Duty (1999-2016) :: 2015 - Alignment Of Front Spline On Rear Driveshaft?

Proper alignment and re-installation of the front spline on the rear driveshaft of my 2015 F350.

I removed my rear driveshaft recently (it slipped right out upon removal without any force or resistance), and I'm getting ready to re-install it again this weekend, but I've noticed that one of the grooves between the array of male splines on the shaft itself appears to be slightly different than the rest - it seems to be slightly wider. It even has a white-colored stripe of paint down the full length of the groove as if it were denoting it as being somehow different from the rest?

Problem is, when visually inspecting the splines on the inside of the receiving yoke (the part that the spline fits into), I do NOT see any such differences. In other words, it doesn't appear that there is only ONE way to properly insert the front splined-end of the driveshaft. What am I missing here?

Is the front splined-end of the rear driveshaft intended to be inserted into the yoke in ANY position around the dial? Or is there only ONE specific position or orientation that it is intended to be inserted or installed? NOTE: I've seen references elsewhere on-line that seem to indicate the need for proper alignment when there are multiple U-Joints, and maybe this is a part of it (?), but I'm not quite sure which U-Joints to consider or how to interpret such an "alignment".