Substitutions also affected by position of numerals
Sometimes rules changes show up in a place that is least expected. In addition to the standard rules changes voted by owners each year, a few editorial changes are made to the rulebook, some of which are for clarity, while others are actual low-level rules changes. Two of those changes appears before the page marked “Rule 1.”
After the table of contents is a schematic of the NFL football field, with all the dimensions and distances of lines, numerals, and hashmarks with tolerances down to ¼ inch. It’s been a staple of the NFL rulebook since at least the 1940s, at the time complete with diagrams showing H-style goalposts, and it’s the page that is quickly skimmed past.
Except, this diagram in the 2020 rulebook has a new addition addressing the team logo at midfield:
Center logos, whether painted or inlayed, may not exceed 1200 square feet or extend beyond the 40-yard lines, whichever occurs first. Square footage will be calculated using the logo art and a 1×1 grid to accurately measure the logo.
This certainly prevents an overzealous owner from decorating their field like Texas A&M-Commerce did in 2013. Their gold lion graphic stretched sideline to sideline and touched both 25-yard lines. Maintenance of this behemoth midfield logo — encompassing over a half an acre — was too much, and a downsize to a 10×12-yard adornment was made in 2019.
The NFL added a rule in 2011 that mandated all artificial turf be a league-approved shade of green, preempting an owner’s amazing technicolor dream coat of paint flooding the field.
One other change to the field in 2020: the numerals will be moved 2 yards closer to the center of the field. Previously, the top of the numbers were 12 yards from the sideline; this year the baseline of the numbers must be 12 yards from the sideline. (The height of the numerals is 2 yards.) This has a specific rule application: any incoming substitute (one that did not participate in the previous play) must enter the field at least to the inside of the numerals (14 yards). Failure to reach the inside of the numbers is a 5-yard illegal substitution. After that, a player may line up outside of the numbers, as long as he is not within 5 yards of the bench area, which would be an unsportsmanlike conduct foul for an illegal hideout.
As for the logo rule, this might have been previously addressed as a guideline in one of the many gameday operations manuals from the league, but at least now it is clearly placed in the rulebook with very clear direction on how the football operations department will determine compliance.