| April 9, 1957 | Communication Center | L. Ron Hubbard writes HCOPL 'Communication Center'. | |
| May 1, 1957 | Comm Center, Arrangement Of | L. Ron Hubbard writes HCOPL 'Comm Center, Arrangement Of'. | |
| July 29, 1957 | Withholds and Communication | L. Ron Hubbard writes HCOB 'Withholds and Communication'. | |
| January 15, 1958 | Field Office Communication | L. Ron Hubbard writes HCOB 'Field Office Communication'. | |
| February 25, 1958 | Routing of Communication | L. Ron Hubbard writes HCOPL 'Routing of Communication'. | |
| July 30, 1958 | The Handling of Hubbard Communications Offices | L. Ron Hubbard writes HCOB 'The Handling of Hubbard Communications Offices'. | |
| December 20, 1958 | HCO Communicator Basic Hat and Comm System, HCO Offices | L. Ron Hubbard writes HCOPL 'HCO Communicator Basic Hat and Comm System, HCO Offices'. | |
| March 2, 1959 | HCO Theory of Communication | L. Ron Hubbard writes HCOPL 'HCO Theory of Communication'. | |
| March 25, 1959 | HAS Co-audit and Comm Course | L. Ron Hubbard writes HCOB 'HAS Co-audit and Comm Course'. | |
| April 3, 1959 | HAS Co-audit and Comm Course | L. Ron Hubbard writes HCOB 'HAS Co-audit and Comm Course'. | |
| August 7, 1959 | The Handling of Communication Processes, Some Rapid Data | L. Ron Hubbard writes HCOB 'The Handling of Communication Processes, Some Rapid Data'. | |
| October 14, 1959 | Comm Speed | L. Ron Hubbard writes HCOPL 'Comm Speed'. | |
| October 29, 1959 | Communication Process Includes Havingness | L. Ron Hubbard writes HCOB 'Communication Process Includes Havingness'. | |
| August 4, 1963 | E-Meter Errors, Communication Cycle Error | L. Ron Hubbard writes HCOB 'E-Meter Errors, Communication Cycle Error'. | |
| February 9, 1964 | Comm Baskets | L. Ron Hubbard writes HCOPL 'Comm Baskets'. | |
| September 9, 1964 | Purpose of Ad Comm | L. Ron Hubbard writes HCOPL 'Purpose of Ad Comm'. | |
| February 22, 1965 | Executive Director Comm Lines | L. Ron Hubbard writes HCOPL 'Executive Director Comm Lines'. | |
| April 1, 1965 | HCO Communicator Has Program Checking Hat LRH Comm N/W Series 21 | L. Ron Hubbard writes HCOPL 'HCO Communicator Has Program Checking Hat LRH Comm N/W Series 21'. | |
| April 22, 1965 | Level 0 Comm Course | L. Ron Hubbard writes HCOPL 'Level 0 Comm Course'. | |
| April 22, 1965 | Level 0 Comm Course | L. Ron Hubbard writes HCOPL 'Level 0 Comm Course'. | |
| May 26, 1965 | Communications, Registered Mail | L. Ron Hubbard writes HCOPL 'Communications, Registered Mail'. | |
| May 26, 1965 | Communications, Registered Mail | L. Ron Hubbard writes HCOPL 'Communications, Registered Mail'. | |
| June 11, 1965 | Correction to HCOPL 26 May 65 II, Communications, Registered Mail | L. Ron Hubbard writes HCOPL 'Correction to HCOPL 26 May 65 II, Communications, Registered Mail'. | |
| June 11, 1965 | Correction to HCOPL 26 May 65 II, Communications, Registered Mail | L. Ron Hubbard writes HCOPL 'Correction to HCOPL 26 May 65 II, Communications, Registered Mail'. | |
| July 1, 1965 | Comm Cycle Additives | L. Ron Hubbard writes HCOPL 'Comm Cycle Additives'. | |
