Topic summary
Hash marks
Extracted from the Wikipedia article Hash mark (sports).
Usage in gridiron football
In American football and Canadian football, the hash marks are two rows of lines near the middle of the field that are parallel to the side lines. These small lines (4 in [10 cm] wide by 2 ft [61 cm] long) are used to mark the 1-yard sections between each of the 5-yard lines, which go from sideline to sideline. All plays start with the ball on or between the hash marks. That is, if the ball is downed in between a hash mark and the nearest sideline, it must be placed on that hash mark for the next play.