Geared Hub Markings?

[cruzinz28]

Has anyone seen their Gear Reduction Hubs Marked like this? Not sure if it was for easy identification on where the cover was or if it meant something else. All four are marked like this.

I noticed it about a month ago when I had to remove and fix my leaking front right tire and forgot to post the question.

 

[ari]

probably indicating the spindle nut was checked. I know alot of them have initials on the cover from when they where in service so the unit would know who to crucify should the wheel fall off