ERASABLE
| Date | Clue |
|---|---|
| 2019-06-29 | Like chalk on a chalkboard |
| 2013-08-08 | Unlocked, as a computer file |
| 2012-11-07 | Like some compact discs |
| 2011-08-28 | Not permanent |
| 2010-06-11 | Impermanent |
| 2008-04-27 | Like some pens |
| 1998-04-24 | Not permanent |
| 1994-12-30 | Penciled-in |