3rd generation Buck with "S" marking

[Carlo]

Take a look at this auction
http://www.ebay.com/itm/PHROBIS-III-...item1e68b03c34
Apart from the "australian scabbard" note the "S" marking on the blade.
What is very interesting is that the bayonet is not a second generation, like shown here (many links inside).
http://www.quarterbore.net/forums/showthread.php?t=3586.
I think it is for me the first time I see the "S" stamp on a military contract 3rd generation M9