Historical clue formulations

• Protect — 2021-10-24
• Captain America carries one — 2017-07-03
• BP logo shape until 2000 — 2015-01-18
• Protect — 2014-09-28
• Take blows for — 2014-01-26
• Warrior's aid — 2013-09-24
• Protect — 2010-05-30
• Bulwark — 2010-03-21
• Ozone layer, for one — 2006-04-02
• Safeguard — 2005-07-13
• Cop's badge — 2005-05-10
• Arrow stopper, perhaps — 2000-06-10
• Guard — 1998-03-05
• Police badge — 1996-01-11
• Protective layer — 1995-12-23
• Protect — 1995-04-19