| Letter Circular No. | Title |
| Letter Circular No. 2021-14 | List of Submitting Entities in Production as of 31 December 2021 |
| Letter Circular No. 2021-12 | List of Submitting Entities in Production as of 26 November 2021 |
| Letter Circular No. 2021-11 | List of Submitting Entities in Production as of 25 October 2021 |
| Letter Circular No. 2021-10 | List of Submitting Entities in Production as of 24 September 2021 |
| Letter Circular No. 2021-09 | List of Submitting Entities in Production as of 27 August 2021 |
| Letter Circular No. 2021-08 | List of Submitting Entities in Production as of 23 July 2021 |
| Letter Circular No. 2021-07 | List of Submitting Entities in Production as of 25 June 2021 |
| Letter Circular No. 2021-05 | List of Submitting Entities in Production as of 21 May 2021 |
| Letter Circular No. 2021-04 | List of Submitting Entities in Production as of 23 April 2021 |
| Letter Circular No. 2021-03 | List of Submitting Entities in Production as of 29 March 2021 |
| Letter Circular No. 2021-02 | List of Submitting Entities in Production as of 28 February 2021 |
| Letter Circular No. 2021-01 | List of Submitting Entities in Production as of 29 January 2021 |