A new change to Ranked Battles has been announced for Pokémon Scarlet and Violet. Read on below to learn more:
Announcing a Term Update from “Series” to “Regulations”
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.
To learn which regulation set is being followed during a Ranked Battles season or official Online Competition, please refer to an event’s respective article.
Source: Pokémon Scarlet and Violet news
Pokémon Blog 
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