| 2026-04-07 | Secretly loop in on an email |
| 2025-12-06 | Email abbr. |
| 2025-10-14 | Secretly loop in, in a way |
| 2025-07-19 | "Moving to ___" (email phrase) |
| 2025-04-18 | Discreetly fill in, in a way |
| 2025-02-08 | Covert field? |
| 2025-01-21 | Surreptitiously let in on an email |
| 2023-08-13 | Concealed field, for short |
| 2023-03-03 | Email letters |
| 2023-01-24 | Include covertly in an email thread |
| 2021-08-10 | Secretly loop in by email |
| 2021-05-18 | Loop in on the DL |
| 2020-10-08 | Secretly include, maybe |
| 2020-08-11 | Loop in secretly, in a way |
| 2019-06-07 | Include surreptitiously, in a way |
| 2019-01-08 | Abbr. in an email field |
| 2018-12-16 | Emailing option |
| 2018-08-21 | Include covertly in an email |
| 2018-02-25 | Include without notifying others, in a way |
| 2018-02-19 | Send covertly, as an email |
| 2018-01-05 | Include discreetly, in a way |
| 2017-10-17 | Secretive email option |
| 2016-01-17 | Email letters |
| 2015-09-16 | Email add-on |
| 2015-04-26 | Include surreptitiously, in a way |
| 2014-03-30 | Abbr. at the top of an email |
| 2013-08-03 | Secret attachment, for short |
| 2012-08-08 | Letters in front of an e-mail address |
| 2011-04-24 | E-mail add-on |
| 2008-10-02 | Abbr. atop some e-mails |
| 2007-08-05 | Abbr. on top of some e-mails |