ITU Operational Bulletin
Messages complement to ITU-T Recommendation
ITU-T Recommendation T.840.4
T.840.4
Last approved: 31.V.2026
Referenced in 1 issue of the Bulletin.
2026
1 amendmentDate / Message
Messages complement to ITU-T Recommendation
Last approved: 31.V.2026
Referenced in 1 issue of the Bulletin.