ZBAR
| Date | Clue |
|---|---|
| 2017-04-13 | Letter-shaped construction piece |
| 2015-10-08 | Doubly bent construction piece |
| 2011-04-05 | Letter-shaped beam |
| 2007-09-19 | Letter-shaped beam |
| 2005-07-21 | Construction piece shaped like the last letter of the alphabet |
| 2002-01-14 | Letter-shaped construction piece |
| 2000-08-13 | Letter-shaped construction piece |