Historical clue formulations

• As required, after "if" — 2024-09-11
• As required, after "if" — 2017-06-05
• Necessary — 2010-05-07
• Required — 2008-08-23
• Required — 2007-01-11
• As required, after "if" — 2004-05-09
• Should it be required, after "if" — 2003-11-30