Effective today, the OCG has introduced two changes to the tournament rules for some of their events. Specifically:
・ランキングデュエル (Ranking Duels)
・遊戯王の日 (Yu-Gi-Oh! Day)
・デュエリスト交流会 (Duelist Meetup)
“and others”

For Section 1 (Items Necessary for Events), Point C (Acceptable Items), Deck Coasters are now allowed.

More importantly, for Section 2 (Tournament Rules), Point D (Declaring Surrender (Defeat in a Duel)), the rules read as follows:

デュエルの進行中に自らの敗北が決定的であると判断した場合において、デュエルの途中でサレンダー（デュエルの敗北）を対戦相手に申告し、その後速やかにジャッジに報告を行うことで、ジャッジはデュエルの敗北を適用することができる。

サレンダーはデュエルの敗北のみに適用され、マッチの敗北は申告することができない。
サレンダーを申告した結果によってマッチの成績が決定する場合は申告することができない。

“If, during the progress of the Duel, a player has determined their own defeat, by declaring their surrender (defeat in the duel) to their opponent during the Duel, and then promptly announcing it to a judge, the judge can enforce the defeat.
-Surrendering only enforces defeat in a Duel, and a defeat for a Match cannot be declared.
-If declaring surrender would decide the result of a Match, surrender cannot be declared.”

Source.

As a reminder, the official tweet summarizing the changes mentions that tournament rules vary depending on each event, and to refer to the website for each event accordingly.

For context, for a very long time, the OCG did not have official rules for surrendering in sanctioned tournaments. While surrendering was generally acceptable in non-sanctioned tournaments, the lack of proper surrendering procedures in official tournaments lead to various undesirable scenarios. Starting on 2023, a select number of high-tier sanctioned events such as the Area Championship officially introduced the same rules as above (with an additional restriction on extra turns/extra Duels). This update is officially adding surrendering for sanctioned tournaments of lower tiers, after many, many years without such a rule.