What are the sin bin, exclusion and dismissal rules for players?

• Misconduct that can bring a penalty, forced interchange, sin bin or dismissal includes: continuous or regular breaches of the rules, swearing towards a player, referee, spectator or official, disputing decisions, using more than the necessary force to make a touch, poor sportsmanship, tripping, striking or assaulting someone, and any other action against the spirit of the game.
• Forced interchange: the referee stops the match, tells the player why, sends them to the interchange area and awards a penalty to the other team.
• Sin bin: a player sent to the sin bin stands in the sin bin area at the opposition's end, on the same side as their interchange area, for four completed possessions. They count as a player on the field and cannot be replaced or interchanged. They must return to the interchange area before re-entering the field.
• Exclusion: if the defending team is penalised three times on entering their seven metre zone in one possession, the last offending player is excluded until the end of that possession.
• Dismissal: the player takes no further part in the match, must stay outside the perimeter, cannot be replaced, and under the national body's disciplinary regulations receives an automatic two match suspension.
• Only team captains may ask the referee about a decision, during a break in play or at the referee's discretion.

Source: FIT Playing Rules 5th Edition, definitions and rules 20 to 23 and 25.2.