"Be Clear" is the motto of the NFL's new bag policy, once which went into effect week one of preseason. The new rules limit the size, and type of bags brought into stadiums -- while offering alternatives so fans can still have personal effects. Large bags are limited to see-through plastic, which small clutch purses are only allowed if they're roughly the size of a hand.
Standard large bags are no longer permitted. Fans can purchase a clear plastic tote bag from either the team store at the stadium, or through the NFL Shop website. Those who elect not to buy a tote will have the option to bring their own, provided it's clear plastic or PVC and does not exceed 12" x 6" x 12."
A second alternative is offered for fans to bring a gallon-sized clear resealable bag. The only non-clear bags permitted will be small clutch-type handbags, roughly the size of a hand, that do not exceed 4.5" x 6.5."
Recent events stemming from the Boston Marathon bombing helped shape the changes, but that was just one factor. The NFL discussed its decision in the FAQ section of their bag policy page on the NFL's official site.
That was a factor to take into account, certainly, but we update and improve the policy every year. It has evolved so that we can continue to adjust to the realities of public safety. We had been discussing a new approach to bag restrictions before the Boston Marathon incident. We have come up with a way to do it that will actually make access more convenient for fans than it has been. We think the fans will embrace and appreciate it.
While the bags listed in the policy are allowed, the NFL strongly suggests fans refrain from bringing them to the stadium to expedite queue lines at games. Additional exceptions can be made for fans with extenuating medical circumstances, and are subject to additional checks at stadium gates.