| LS | Title | From | To | Approval date |
| SG17-LS315 | LS/r on latest activities on IoT security in ITU-T SG17 (reply to SG20-LS223) | SG17 | SG20; | 2021-09-03 |
| SG20-LS223 | LS/r on increasing efficiency of security work in ITU-T (reply to SG17-LS269) | SG20 | SG11; SG13; SG17; TSAG; | 2021-05-27 |
| SG15-LS264 | LS/r on WTSA-21 preparations (reply to TSAG-LS27) | SG15 | TSAG; | 2020-09-18 |
| SG2-LS167 | LS/r on WTSA-20 preparations concerning work programme and structure (reply to TSAG-LS27) | SG2 | TSAG; | 2020-09-07 |
| SG17-LS269 | LS/r on increasing efficiency of security work in ITU-T (reply to TSAG-LS27) | SG17 | TSAG; SG11; SG13; SG20; | 2020-09-03 |
| SG17-LS285 | LS/r on draft ITU-T Study Group 17 REPORTs TO WTSA-20 - PART I - GENERAL (Annex 2 only), and Part II - QUESTIONS for the next study period (2021 - 2024) (reply to TSAG-LS27) | SG17 | TSAG; | 2020-09-03 |
| SG3-LS90 | LS/r on WTSA-20 preparations (reply to TSAG-LS20, TSAG-LS27) | SG3 | TSAG; | 2020-08-28 |
| SG20-LS166 | LS/r on WTSA-20 preparations concerning work programme and structure (reply to TSAG-LS27) | SG20 | TSAG; | 2020-07-16 |
| SG5-LS139 | LS/r on WTSA Preparation (reply to TSAG-LS27) | SG5 | TSAG; | 2020-05-20 |
| SG17-LS237 | LS/r on interim draft ITU-T Study Group 17 REPORTs TO WTSA-20 - PART I - GENERAL (Annex 2 only), and Part II - QUESTIONS for the next study period (2021 - 2024) (reply to TSAG-LS27) | SG17 | TSAG; | 2020-03-26 |
| TSAG-LS27 | LS on WTSA-20 preparations concerning work programme and structure [to all ITU-T SGs] | TSAG | SG2; SG3; SG5; SG9; SG11; SG12; SG13; SG15; SG16; SG17; SG20; | 2020-02-14 |
| TSAG-LS20 | LS on WTSA-20 preparations | TSAG | SG2; SG3; SG5; SG9; SG11; SG12; SG13; SG15; SG16; SG17; SG20; | 2019-04-11 |
