Historical clue formulations

• ERNE — 2014-02-25
• Erne or tern — 2014-02-02
• Stilt, e.g. — 2009-08-16
• Erne or tern — 2002-05-28
• Albatross, e.g. — 2001-04-28
• Albatross, e.g. — 2000-01-11