PLANAR
| Date | Clue |
|---|---|
| 2023-05-06 | Two-dimensional |
| 2022-12-03 | Like a flat surface |
| 2021-03-05 | Two-dimensional |
| 2014-08-01 | Two-dimensional |
| 2014-06-01 | Like Flatland |
| 2012-11-04 | Two-dimensional |
| 2011-04-27 | Flat |
| 2005-12-13 | Two-dimensional |
| 2001-10-28 | Flat |
| 1997-04-09 | Two-dimensional |
| 1994-01-29 | Two-dimensional |