Hmm, hard to truly understand. Here is what Wikipedia says:
"The NFL implemented a revised third quarterback rule for the
2023 NFL season in response to the
49ers sustaining injuries to both of their active quarterbacks in the
NFC Championship Game.
[4] The third quarterback can be placed on an inactive roster spot where he would not use a spot on the 53 player active roster. He may enter the game if the quarterbacks on the active roster are injured or disqualified. Unlike with the rule put in place in 1991, if a quarterback from the active roster is medically cleared to enter the game he may do so and the third quarterback must leave the game.
[5]"
https://en.m.wikipedia.org/wiki/Third_quarterback_rule#:~:text=The third quarterback can be,roster are injured or disqualified.
Here is what the NFL's website says:
"Full language of the updated bylaw:
One hour and 30 minutes prior to kickoff, each club is required to establish its Active List for the game by notifying the Referee of the players on its Inactive List for that game. Each club may also designate one emergency third quarterback from its 53-player Active/Inactive List (i.e., elevated players are not eligible for designation) who will be eligible to be activated during the game, if the club's first two quarterbacks on its game day Active List are not able to participate in the game due to injury or disqualification (activation cannot be a result of a head coach's in-game decision to remove a player from the game due to performance or conduct). If either of the injured quarterbacks is cleared by the medical staff to return to play, the emergency third quarterback must be removed from the game and is not permitted to continue to play quarterback or any other position, but is eligible to return to the game to play quarterback if another emergency third quarterback situation arises.
A club is not eligible to use these procedures if it carries three quarterbacks on its game day Active List [47- or 48-players in 2023]."
https://www.nfl.com/news/nfl-owners...eams-to-have-third-qb-active-on-game-days-wit
Still confusing...