Historical clue formulations

• Register printout — 2015-05-06
• It often says "Thank You" — 2015-03-06
• It often comes with a "Thank You" — 2013-07-13
• Slip on a new piece of clothing? — 2005-10-08
• Return requirement? — 2003-04-25
• Register output — 2002-03-02
• Register printout — 2001-12-19
• Proof of purchase — 1999-08-09
• Ticket stub, e.g. — 1998-08-23