This box would be redundant - for the games based on quizzes, ALL quizzes are eligible except those way too specialized (you wouldn't see stuff about a specific episode of a TV show). If fact editors do have the opposite button to specifically exclude a specific question from consideration in case it does cause problems in the game.
For TvT and, increasingly, other games, we use the single questions which are inherently an ever-growing pool. With the daily challenges now involving writing these questions, we see quite good growth there, so more and more games will use that pool.
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FT Editor and Administrator
Guardian of the Tower