| 2024-12-12 | Writes in C or R, say |
| 2024-12-05 | Does programming work |
| 2024-09-21 | Works on a loop, say |
| 2023-07-10 | Message concealers |
| 2023-02-09 | Does some tech work |
| 2020-09-05 | Things that can be cracked |
| 2018-09-28 | Does some computer work |
| 2016-12-13 | Does a tech job |
| 2015-11-08 | Writes in C++, say |
| 2013-05-14 | Secret writings |
| 2012-12-06 | Programs |
| 2012-09-11 | Does some computer programming |
| 2011-06-19 | "One if by land, two if by sea" and others |
| 2008-08-23 | Buildings often have them |
| 2007-05-14 | Secret languages |
| 2006-02-08 | See 5-Across |
| 2004-07-22 | They may be cracked |
| 2002-11-10 | Computer programmers' expertise |
| 2002-05-17 | Crackers may be used on them |
| 2001-09-12 | Things to crack |
| 2001-08-26 | Systems of rules |
| 1999-07-09 | Some are made of bars |
| 1997-11-25 | Things to crack |
| 1996-01-09 | Spy secrets |