Historical clue formulations

• Coach's lack, often — 2026-07-25
• What's lacking in a crowded elevator — 2026-03-07
• What one might hope for in a tight spot — 2023-12-29
• Adequate space to move around ... as found in this puzzle's circled letters? — 2022-08-16
• It's hard to find in a crowd — 2016-09-16
• Shortage in a rush-hour subway — 2008-07-25