With teams having recently cut their rosters down from 90 players to 75, and then to 53, and then adding 10 to their practice squad, this is the time on the NFL calendar when roster maneuvering is at its peak. That means now is a good time to take a look at the Collective Bargaining Agreement and take a refresher on some of the rules and procedures NFL teams must abide by for the regular season.

Active List
A team's Active List (roster) cannot exceed 53 players.

Game Day Roster
A team's Active List on game day must consist of no more than 46 players and no fewer than 43. Players who are on the 53-man roster but are not active on game day are placed on the Inactive List.

Practice Squad
A player is eligible for the Practice Squad if he has fewer than three practice squad seasons (a PS season = on the PS for at least six weeks) and one of the two following apply to him – the player does not have an accrued season of credit or the player does have an accrued season but he was on the 46-player active roster for fewer than nine regular season games during each accrued season. A team can have 10 such PS players at any time.

There is also a new Practice Squad exception rule of which a team may have two players. The exception is for players who do not have more than two accrued seasons and who have fewer than three practice squad seasons.

Reserve/Injured
Except for players who are subject to the rules for injury settlements or who have been "Designated for Return" (more on that below), players who are placed on the Reserve/Injured List at any time are prohibited from playing and/or practicing for the rest of the season, including postseason, with the club that placed them on the Reserve/Injured List.

If a club subsequently waives or otherwise terminates a player on the Reserve/Injured List, the club is prohibited from re-acquiring such a player during the 2015 regular season and postseason.

Players on the Reserve/Injured List may not be traded.]

Players who are placed on the Reserve/Injured List with less than a six-week injury (an inability to practice or play for six weeks, measured from the date of the injury) must be waived/terminated as soon as they are again able to practice or play. Players placed on the Reserve/Injured List with a "major" injury (loss of time expected to be at least six weeks) may remain on the Reserve/Injured List for the remainder of the season and return to the club's Active List following the season.

Reserve/Injured (Designated for Return)
During each season, a club will be permitted to return one player from the Reserve/Injured List to its 53-player Active List. Such player must have suffered a "major" football-related injury after reporting to training camp and must have been placed on the Reserve/Injured List after the final roster reduction (September 5).

A player who is eligible to return must be noted as "Designated for Return" at the time the player is placed on the Reserve/Injured List.

A player who has been designated for return is ineligible to practice until six weeks have elapsed since the date he was placed on the Reserve/Injured List, and is not eligible to return to the Active/Inactive List until eight weeks have elapsed since the date he was placed on the Reserve/Injured List.

At any time after the conclusion of the sixth week that a player designated for return has been on the Reserve/Injured List, a club is permitted to return him to practice for a period not to exceed 21 calendar days. Provided that the player has been on Reserve/Injured for at least eight weeks from the date he was placed on Reserve, a club is permitted to return him to its Active/Inactive List at any time during the 21-day period. If the player is not returned to the Active/Inactive List on the day after the conclusion of the 21-day period, he is not eligible to return to that club's Active/Inactive List for the remainder of the season and postseason. If the club elects to continue to carry the player on Reserve/Injured, the player shall not be permitted to practice or to participate in team or individual drills during the remainder of the season, including postseason.

Reserve/Physically Unable to Perform (Reserve/PUP)
Players in this category do not count against the 53-man roster limit.

Players in this category are limited to non-contact rehabilitative work under the supervision of the club's trainer or physician, and such player are permitted to attend team meetings and may also attend (but not participate in) practice.

Commencing on the sixth calendar day prior to a club's seventh regular season game (including a bye week) and continuing through the day after the conclusion of the 11th regular season weekend (November 24), clubs are permitted to begin practicing players on Reserve/PUP for a period not to exceed 21 days.

If the player is not restored to the Active/Inactive List prior to the conclusion of the 21-day period, and the club elects to continue to carry the player on Reserve/PUP, the player shall not be permitted to practice or to participate in team or in during the remainder of the season, including postseason.

Players on the Reserve/PUP List may not be traded.