Historical clue formulations

• Transcript ruiners — 2025-12-25
• Failing grades — 2020-02-24
• Symbols of failure — 2020-02-16
• Lots of fluff? — 2018-07-10
• Letters before gees — 2017-06-26
• Bad grades — 2016-03-16
• Pair of buffalo? — 2011-08-05
• Pair of ruffians? — 2010-07-25
• Bad grades — 2010-06-15
• They keep you from passing — 2009-02-22
• Sign of poor schoolwork — 2004-12-29
• Failing marks — 2003-12-17
• Flunking marks — 2003-05-27
• This puzzle's surplus — 2001-12-16
• Rotten grades — 2001-10-28
• They can make a suer suffer — 2001-09-16
• Two of fifty? — 1999-08-06
• Report card woes — 1995-06-11