All of the above?
Nebraska has been nationally known for a rushing attack, which includes HB/FB and OL, which has its own nickname (Pipeline). We also have a national OL award named for Rimington, and there's now a PK Return award named for The Jett.
But then again, Blackshirts. Our defense has been known as grave diggers for opposing teams.
And special teams. We seem to have an abundance of walk-on soccer players like Koch, Brown, Henery and others that practically never ends. I've watched too many Oregon Duck games were the kicker missed multiple 35 yard FGs to know that Nebraska somehow always has serviceable kickers.
For me, it's not so much a position as a philosophy. Heavily-conditioned ground attack that wears opponents out (Warren Sapp, anyone?) and an attacking defense that swarms the other team's ball carriers. If you watch old Blackshirt highlights there were almost always 2, 3 or 4 defenders hitting the ball carrier at once.