Historical clue formulations

• Character appearing twice in "Dumb and Dumber"? — 2024-07-28
• The fourth letter of "bomb," but not the first — 2024-03-26
• Element of doubt? — 2022-07-05
• Thing in doubt? — 2014-01-05
• One in debt? — 2010-05-22
• Thumb's end — 2007-11-22