Historical clue formulations

• Violins and violas: Abbr. — 2015-08-16
• Cellos, violas, etc.: Abbr. — 2011-03-08
• Navigation rtes. — 2009-10-24
• Orch. section — 2008-06-29
• Orch. section — 2008-03-28
• Orch. section — 2002-10-20
• Violins and violas: Abbr. — 2002-04-16