SRO means "standing room only" and these are usually the cheapest tickets for a Cowboys game, sometimes as low as $6. There are West and East SRO sections and they are located above the endzones above the 300 level sections. You'll sometimes see these listed as "Party Pass", "E SRO", "W SRO". Arrive early to hold a good spot and bring a buddy in case you need to make a drink or food run since there's no assigned areas.