NFL approves 7 new rules for 2021 season including single digit
Changes to overtime, jersey numbers among 11 rule proposals on
The NFL 2020-2021 Season: How This Year's Game Will Be Different
History of Instant Replay
2021 NFL rule changes: Expanded jersey numbers among 6 new rules
Breaking down the NFL's 6 new rules for 2021 season - Pride Of Detroit
NFL owners approve rule changes, including no preseason overtime
NFL owners approve replay change, other new rules for 2021 season
NFL owners approve rule change for overtime in playoffs
Instant replay on table for NFL owners - The Boston Globe
The replay timing rule change that's not in the rulebook
NFL schedule-release date, plus owners approve several rule
New NFL jersey number rules allow single digits for defense