Historical clue formulations

• Sack dress? — 2014-03-01
• Some silk threads — 2013-02-09
• Nightwear ... or a hidden feature of 17-, 21-, 33-, 41-, 54- and 59-Across? — 2012-10-10
• Sleepers — 2010-10-12
• Some are flannel — 2010-06-08
• Nightclothes — 2007-04-30
• Playboy's wear — 2004-05-16
• See 11-Down — 2003-12-18
• Sleepers — 2001-11-08
• Cat's ___ — 2001-02-10
• Nightcap accompaniment — 1995-05-18