Historical clue formulations

• Scribble absentmindedly — 2022-08-15
• Art often of marginal quality? — 2019-09-11
• Output during a boring meeting, say — 2018-05-10
• Idle drawing in a margin — 2015-02-16
• Kilroy, e.g. — 2011-04-02
• Drawing in a margin, maybe — 2010-04-08
• Daydreamer's doing — 2009-06-28
• It may result from a long phone conversation — 1999-01-16