Tom Osborne built up the Cornhusker football program in the late '80s through the mid '90s through liberal use of the NCAA's Proposition 48 eligibility rules, which were enacted in 1986. Apparently, there were legitimate ways to sign what were termed partial qualifiers, for instance, athletes who met either the SAT/ACT minimum, but did not have the grades in HS.
Here is an article from SI in January 1996, which foretold, with startling accuracy, the pending decline of Nebraska football :
Nebraska may win another national title, but the days - 01.15.96 - SI Vault
The Big 8 did not restrict partial qualifiers, but Big Red was forever changed when the Big 12 prohibited partial qualifiers. Nowadays, athletes like this, I presume, are classified as non-qualifiers and are redirected to the Iowa Western CC's of the world.
What lies ahead? Big Red may just recover over the next 10 years. Here's a summary from ESPN's Michael Rothstein from this past summer's dialogue on NCAA reform. Take note of Point 3 regarding accommodation of "at-risk" student athletes, which could provide a crack in the door for the return of Nebraska football:
Big Ten commisioner Jim Delany pitches NCAA reform plan - ESPN
And some speculation from the Husker 24/7 site regarding the same:
Sounds like delany wants to bring back Prop 48