Steady snowfall turned Highmark Stadium into a winter wonderland for the “Sunday Night Football ... With the field covered in white powder, NBC superimposed digital yard lines and numbers ...

There are also cases where the yard lines are very poorly marked ... It is a standard practice at all levels of football for officials to inspect the field before the contest to verify all lines ...

In anticipation of teams electing to concede field position from the 30-yard line on purposeful touchbacks (either on bounces or through the end zone), NFL chief administrator of football ...