"The St. Louis Rams' future here could be in question because of two words that many fans don't usually associate with the Edward Jones Dome: first tier.

Those words give the Rams a door to walk away from the team's lease at the Dome — the building has to be a "first-tier" stadium by 2015, or among the top 25 percent of National Football League venues.

The lease itself, however, doesn't offer much clarity on what constitutes first tier. It identifies several components that need to meet that bar, but also includes vague factors, such as "the physical structure of the facilities." Another says simply 'stadium seating."

The lease includes enough broad language that negotiators could argue just about every inch of the Dome is subject to the standard."