The regulations followed during Ranked Battles seasons and official Online Competitions—previously organized by “series” number—will now be named alphabetically and collectively referred to as “regulation sets.” See an example below.

Before: Ranked Battles Season 1 will follow the Series 1 regulations.
After: Ranked Battles Season 1 will follow Regulation Set A.

Note that the use of “season,” a term describing the duration of a Ranked Battles competition period, remains unchanged.

Announcing Regulation Set C for Ranked Battles!

Event Schedule: Saturday, April 1, 2023, at 00:00 UTC to Friday, June 30, 2023, at 23:59 UTC

Battle Format

Eligible Pokémon: Paldea Pokédex No. 001–398 are eligible to participate.

Certain Pokémon may not be used. Only Pokémon obtained in the Pokémon Scarlet or Pokémon Violet games are eligible.

Banned: Charmander, Charmeleon, Charizard, Meowth, Wooper, Quagsire, Zorua, Zoroark, Froakie, Frogadier, Greninja, Scorbunny, Raboot, Cinderace, Perrserker, Koraidon, Miraidon, Walking Wake, Iron Leaves

Pokémon Levels

All Pokémon will automatically be set to Lv. 50 during battles.

Held Items

Duplicate held items are not allowed.

Timers

Total Time: 20 minutes
Player Time: 7 minutes
Preview Time: 90 seconds
Turn Time: 45 seconds

What Are Regulations?

Regulations define the rules followed by Trainers around the world during Ranked Battles and official Online Competitions. The same regulations are maintained for the duration of a regulation set. Look out for information on which regulation sets will be used for each Ranked Battles season and official Online Competition.

Any Nintendo Switch Online membership (sold separately) and Nintendo Account required for online features. Membership auto-renews after initial term at the then-current price unless canceled. Not available in all countries. Internet access required for online features. Terms apply.

Battle data and results will be provided to Nintendo Co., Ltd., and The Pokémon Company (and its subsidiaries).

Players engaging in the following activities may receive penalties and be restricted from participating in future online events.
• Use of unauthorized methods to alter game save data, use of Pokémon that have data altered via altering code, or use of Pokémon created via altering code
• Significantly large number of disconnects during battle, from when your opponent has been decided to when the match results have been fully sent to the server (please ensure a stable connection environment when connecting to the internet)
• Troubling behavior that could affect other participants or make others feel unpleasant
• Actions that would obstruct battles and operations, such as hacking
• Registering with incorrect information or impersonating another player
• Other actions that operation hosts determine to be inappropriate

Source: https://sv-news.pokemon.co.jp/en/page/48.html