American Football NCAA Rule 1-2-7-a, b, e and f

a. The yardage chain shall join two rods not fewer than 5 feet high, the rods’ inside edges being exactly 10 yards apart when the chain is fully extended.
b. The down indicator shall be mounted on a rod not fewer than 5 feet high operating approximately six feet outside the sideline opposite the press box.
e. All line-to-gain and down-indicator rods shall have flat ends.
f. Advertising is prohibited on the down and line-to-gain indicators. One manufacturer’s logo or trademark is permitted on each indicator. Institutional and conference logos are allowed.