Mark II Box Labels

[Highstandardguy]

I've noticed that some of the box labels on my Ruger MarkIIs and 22/45s have a large "03" printed about midway on the label and some do not. I can't see any pattern to it's appearance. Can anyone tell me the significance of the 03 and when it should appear?

 

[Highstandardguy]

No ideas I guess. Well I thought I had a hint. It appears on the boxes of my distributer only models except for my MK4B (not MK4BL) which I thought was a regular factory model. Bueller, bueller, bueller.........