Invitations have been sent to the following categories of entities entitled to participate (ref. CV/Art. 23):
- Member States [CV/268]
- CL-21/40: Invitation on behalf of the Government of Romania
- CL-21/41: Invitation from the ITU Secretary-General
- Palestine [Res. 99 (Rev. Dubai, 2018)]
- Observers which participate in an advisory capacity (Annex 2 to Res. 145 (Antalya, 2006)):
- the United Nations [CV/269A]
- regional telecommunications organizations [CV/269B]
- intergovernmental organizations operating satellite systems [CV/269C]
- specialized agencies of the United Nations and the International Atomic Energy Agency [CV/269D]
- DM-21/1021: Invitation from the ITU Secretary-General
- Observers which do not participate in an advisory capacity (Annex 3 to Res. 145 (Antalya, 2006)):
- Sector Members referred to in CV/229 (recognized operating agencies, scientific or industrial organizations and financial or development institutions) and CV/231 (regional and other international telecommunication, standardization, financial or development organizations)
- DM-21/1022: Invitation from the ITU Secretary-General
