Essentially a label of "not a P5 but not a G5 either" which BYU thought was enough of a distinction to pursue Independence. At least in this scenario you get to compete for a conference championship that is meaningful and you have access to the CFP. If BYU, Boise & SDSU joined the AAC they'd be viewed as quasi-P5 programs as they'd be a tier above the western G5 teams and they'd be playing in a conference whose champion was playing in the CFP consistently.