I don't know what all factors get actively added together, but the attendance number
not being the scanned tickets number is absolutely accurate.
"While announced attendance data — which pairs paid tickets with coaches, players, media, game officials and other stadium personnel — routinely puts NU’s attendance at games in the upper 80,000s for recent seasons, Nebraska also keeps track of how many fan tickets are scanned as they enter the stadium gates. It provides an additional layer of insight at fan attendance.
That data shows 79,105 fans had tickets scanned for the CU game, the much-anticipated contest watched by 6.3 million viewers on NBC. NU extracted revenge its 2023 loss in Boulder. Fans stormed the field afterward in celebration."
Scanned ticket totals revealed Nebraska's win over Colorado ranked among the best-attended games in the last decade at Memorial Stadium.
huskerextra.com
"The Buffalo and Ohio State scanned ticket crowds were the third and fourth smallest since 2014, just ahead of 2018 Illinois (54,838 in frigid temperatures) and 2019 Iowa, which had 60,232 scanned tickets.
The 2021 season was the first that had only two games with scanned ticket totals above 70,000, as well. Because the Big Ten didn’t allow fans outside of family and close friends during the COVID-shaped 2020 season, there is no relevant data from that year, and the sellout streak was put on hold.