round wind tiles
Mahjong term: tiles that match the current round wind (場風). These tiles can be used to form a yaku (役) when they match the player's seat wind as well, or when they are part of a pung/kong of the round wind.
I called pung on the round wind tile and secured the yaku.
In the East round, East tiles are the round wind tiles.
自風牌 are tiles matching the player's seat wind, whereas 場風牌 are tiles matching the round wind.
Compound of 場風 (round wind) + 牌 (tile).