CREATE TABLE table_204_392 (id DECIMAL, "#" DECIMAL, "stadium" TEXT, "capacity" DECIMAL, "city" TEXT, "country" TEXT, "domed or retractable roof" TEXT)

is wembley stadium or att stadium larger ?
SELECT "stadium" FROM table_204_392 WHERE "stadium" IN ('wembley stadium', 'at&t stadium') ORDER BY "capacity" DESC LIMIT 1
SELECT "stadium" FROM "table_204_392" WHERE "stadium" IN ('wembley stadium', 'at&t stadium') ORDER BY "capacity" DESC NULLS LAST LIMIT 1