Historical clue formulations

• Kitchen pad — 2015-10-11
• Relative of S.O.S — 2013-12-08
• S.O.S alternative — 2010-10-26
• S.O.S alternative — 2005-01-12
• Warhol's "___ Boxes" — 1997-11-08
• Scratch pad? — 1996-06-16