Historical clue formulations

• Wing: Prefix — 2010-04-24
• Feather: Prefix — 2009-11-21
• Wing: Prefix — 2007-07-29
• Wing: Prefix — 2002-05-21
• Wing: Prefix — 2001-06-10
• Feather: Prefix — 2001-04-05
• Feather: Prefix — 1994-03-06